Editing Embryonic stem cell (section)

==Techniques and conditions for derivation and culture==

===Derivation from humans===
[[In vitro fertilization]] generates multiple embryos. The surplus of embryos is not clinically used or is unsuitable for implantation into the patient, and therefore may be donated by the donor with consent. Human embryonic stem cells can be derived from these donated embryos or additionally they can also be extracted from cloned embryos created using a cell from a patient and a donated egg through the process of [[somatic cell nuclear transfer]].<ref>{{cite journal|last=Mountford|first=JC|title=Human embryonic stem cells: origins, characteristics and potential for regenerative therapy|journal=Transfus Med|year=2008|volume=18|pages=1–12|doi=10.1111/j.1365-3148.2007.00807.x|pmid=18279188|issue=1|s2cid=20874633}}</ref> The inner cell mass (cells of interest), from the blastocyst stage of the embryo, is separated from the trophectoderm, the cells that would differentiate into extra-embryonic tissue. [[Immunosurgery]], the process in which antibodies are bound to the trophectoderm and removed by another solution, and mechanical dissection are performed to achieve separation. The resulting inner cell mass cells are plated onto cells that will supply support. The inner cell mass cells attach and expand further to form a human embryonic cell line, which are undifferentiated. These cells are fed daily and are enzymatically or mechanically separated every four to seven days. For differentiation to occur, the human embryonic stem cell line is removed from the supporting cells to form embryoid bodies, is co-cultured with a serum containing necessary signals, or is grafted in a three-dimensional scaffold to result.<ref>{{cite journal|vauthors=Thomson JA, Itskovitz-Eldor J, Shapiro SS, Waknitz MA, Swiergiel JJ, Marshall VS, Jones JM |title=Embryonic stem cell lines derived from human blastocysts|journal=Science|year=1998|volume=282|pages=1145–1147|doi= 10.1126/science.282.5391.1145|pmid=9804556|issue=5391|bibcode=1998Sci...282.1145T|doi-access=free}}</ref>

===Derivation from other animals===
<!-- Deleted image removed: [[File:ES cell derivation.jpeg|thumb|ES cells are derived from the [[inner cell mass]] of the early embryo.  This schematic shows one method of derivation. {{deletable image-caption}}]] -->
Embryonic stem cells are derived from the [[inner cell mass]] of the early [[embryo]], which are harvested from the donor mother animal.  [[Martin Evans]] and [[Matthew Kaufman]] reported a technique that delays embryo implantation, allowing the inner cell mass to increase.  This process includes removing the donor mother's [[ovaries]] and dosing her with [[progesterone]], changing the hormone environment, which causes the embryos to remain free in the uterus.  After 4–6 days of this intrauterine culture, the embryos are harvested and grown in ''in vitro'' culture until the inner cell mass forms “egg cylinder-like structures,” which are dissociated into single cells, and plated on [[fibroblasts]] treated with [[Mitomycin|mitomycin-c]] (to prevent fibroblast [[mitosis]]).  Clonal [[cell lines]] are created by growing up a single cell.  Evans and Kaufman showed that the cells grown out from these cultures could form [[teratoma]]s and [[Embryoid body|embryoid bodies]], and differentiate ''in vitro,'' all of which indicating that the cells are [[pluripotent]].<ref name="Evans M, Kaufman M 1981 154–6"/>

[[Gail R. Martin|Gail Martin]] derived and cultured her ES cells differently.  She removed the embryos from the donor mother at approximately 76 hours after copulation and cultured them overnight in a medium containing serum.  The following day, she removed the [[inner cell mass]] from the late [[blastocyst]] using [[microsurgery]].  The extracted [[inner cell mass]] was cultured on [[fibroblasts]] treated with [[Mitomycin|mitomycin-c]] in a medium containing serum and conditioned by ES cells.  After approximately one week, colonies of cells grew out.  These cells grew in culture and demonstrated [[pluripotent]] characteristics, as demonstrated by the ability to form [[teratoma]]s, differentiate ''in vitro,'' and form [[Embryoid body|embryoid bodies]].  Martin referred to these cells as ES cells.<ref name="Martin G 1981 7634–8"/>

It is now known that the [[Fibroblast|feeder cells]] provide [[leukemia inhibitory factor]] (LIF) and serum provides [[bone morphogenetic proteins]] (BMPs) that are necessary to prevent ES cells from differentiating.<ref>{{cite journal | vauthors = Smith AG, Heath JK, Donaldson DD, Wong GG, Moreau J, Stahl M, Rogers D| title = Inhibition of pluripotential embryonic stem cell differentiation by purified polypeptides| journal = Nature | volume = 336 | issue = 6200 | pages = 688–690 | year = 1988 | pmid = 3143917 | doi = 10.1038/336688a0| bibcode = 1988Natur.336..688S| s2cid = 4325137}}</ref><ref>{{cite journal | vauthors = Williams RL, Hilton DJ, Pease S, Willson TA, Stewart CL, Gearing DP, Wagner EF, Metcalf D, Nicola NA, Gough NM | title = Myeloid leukaemia inhibitory factor maintains the developmental potential of embryonic stem cells | journal = Nature | volume = 336 | issue = 6200 | pages = 684–687 | year = 1988 | pmid = 3143916| doi = 10.1038/336684a0| bibcode = 1988Natur.336..684W | s2cid = 4346252 }}</ref> These factors are extremely important for the efficiency of deriving ES cells.  Furthermore, it has been demonstrated that different mouse strains have different efficiencies for isolating ES cells.<ref>{{cite journal | vauthors = Ledermann B, Bürki K | title = Establishment of a germ-line competent C57BL/6 embryonic stem cell line | journal = Exp Cell Res | volume = 197 | issue = 2 | pages = 254–258 | year = 1991 | pmid = 1959560 | doi = 10.1016/0014-4827(91)90430-3}}</ref> Current uses for mouse ES cells include the generation of [[transgenic]] mice, including [[knockout mice]].  For human treatment, there is a need for patient specific pluripotent cells.  Generation of human ES cells is more difficult and faces ethical issues.  So, in addition to human ES cell research, many groups are focused on the generation of [[induced pluripotent stem cells]] (iPS cells).<ref>{{cite journal | vauthors = Takahashi K, Tanabe K, Ohnuki M, Narita M, Ichisaka T, Tomoda K, Yamanaka S | title = Induction of pluripotent stem cells from adult human fibroblasts by defined factors | journal = Cell| volume = 131 | issue = 5 | pages = 861–872 | year = 2007 | pmid = 18035408| doi = 10.1016/j.cell.2007.11.019| hdl = 2433/49782 | s2cid = 8531539 | hdl-access = free }}</ref>

===Potential methods for new cell line derivation===
On August 23, 2006, the online edition of ''[[Nature (journal)|Nature]]'' scientific journal published a letter by Dr. [[Robert Lanza]] (medical director of [[Advanced Cell Technology]] in Worcester, MA) stating that his team had found a way to extract embryonic stem cells without destroying the actual embryo.<ref>{{cite journal | vauthors = Klimanskaya I, Chung Y, Becker S, Lu SJ, Lanza R | title = Human embryonic stem cell lines derived from single blastomeres| journal = Nature | volume = 444 | issue = 7118 | pages = 481–485 | year = 2006 | pmid = 16929302 | doi = 10.1038/nature05142| bibcode = 2006Natur.444..481K| s2cid = 84792371}}</ref> This technical achievement would potentially enable scientists to work with new lines of embryonic stem cells derived using public funding in the US, where federal funding was at the time limited to research using embryonic stem cell lines derived prior to August 2001.  In March, 2009, the limitation was lifted.<ref name="restriction_lifted">[https://www.theguardian.com/world/2009/mar/10/obama-stem-cell-research US scientists relieved as Obama lifts ban on stem cell research] {{Webarchive|url=https://web.archive.org/web/20130726203242/http://www.guardian.co.uk/world/2009/mar/10/obama-stem-cell-research |date=2013-07-26 }}, ''[[The Guardian]]'', 10 March 2009</ref>

Human embryonic stem cells have also been derived by [[Somatic cell nuclear transfer|somatic cell nuclear transfer (SCNT)]].<ref>{{Cite journal|last1=Tachibana|first1=Masahito|last2=Amato|first2=Paula|last3=Sparman|first3=Michelle|last4=Gutierrez|first4=Nuria Marti|last5=Tippner-Hedges|first5=Rebecca|last6=Ma|first6=Hong|last7=Kang|first7=Eunju|last8=Fulati|first8=Alimujiang|last9=Lee|first9=Hyo-Sang|last10=Sritanaudomchai|first10=Hathaitip|last11=Masterson|first11=Keith|date=2013-06-06|title=Human Embryonic Stem Cells Derived by Somatic Cell Nuclear Transfer|url= |journal=Cell|language=English|volume=153|issue=6|pages=1228–1238|doi=10.1016/j.cell.2013.05.006|pmid=23683578|pmc=3772789|issn=0092-8674|doi-access=free}}</ref><ref>{{Cite journal|last1=Chung|first1=Young Gie|last2=Eum|first2=Jin Hee|last3=Lee|first3=Jeoung Eun|last4=Shim|first4=Sung Han|last5=Sepilian|first5=Vicken|last6=Hong|first6=Seung Wook|last7=Lee|first7=Yumie|last8=Treff|first8=Nathan R.|last9=Choi|first9=Young Ho|last10=Kimbrel|first10=Erin A.|last11=Dittman|first11=Ralph E.|date=2014-06-05|title=Human Somatic Cell Nuclear Transfer Using Adult Cells|journal=Cell Stem Cell|language=English|volume=14|issue=6|pages=777–780|doi=10.1016/j.stem.2014.03.015|issn=1934-5909|pmid=24746675|doi-access=free}}</ref> This approach has also sometimes been referred to as "therapeutic cloning" because SCNT bears similarity to other kinds of cloning in that nuclei are transferred from a somatic cell into an enucleated zygote. However, in this case SCNT was used to produce embryonic stem cell lines in a lab, not living organisms via a pregnancy. The "therapeutic" part of the name is included because of the hope that SCNT produced embryonic stem cells could have clinical utility.

===Induced pluripotent stem cells===
{{main|Induced pluripotent stem cell}}

The iPS cell technology was pioneered by [[Shinya Yamanaka]]'s lab in [[Kyoto]], [[Japan]], who showed in 2006 that the introduction of four specific genes encoding [[transcription factors]] could convert adult cells into pluripotent stem cells.<ref name="ReferenceA">{{cite journal | last1 = Takahashi | first1 = K | last2 = Yamanaka | first2 = S | title = Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors | journal = Cell | volume = 126 | issue = 4 | pages = 663–676 | year = 2006 | pmid = 16904174 | doi = 10.1016/j.cell.2006.07.024 | hdl = 2433/159777 | s2cid = 1565219 | hdl-access = free }}{{open access}}</ref> He was awarded the 2012 Nobel Prize along with Sir [[John Gurdon]] "for the discovery that mature cells can be reprogrammed to become pluripotent."<ref>{{cite web|url=https://www.nobelprize.org/nobel_prizes/medicine/laureates/2012/press.html|publisher=Nobel Media AB|date=8 October 2012|title=The Nobel Prize in Physiology or Medicine – 2012 Press Release|access-date=3 July 2017|archive-date=4 April 2023|archive-url=https://web.archive.org/web/20230404202940/http://www.nobelprize.org/nobel_prizes/medicine/laureates/2012/press.html|url-status=live}}</ref>

In 2007, it was shown that [[pluripotency|pluripotent]] [[stem cell]]s, highly similar to embryonic stem cells, can be induced by the delivery of four factors (''Oct3/4'', ''Sox2'', c-Myc, and ''Klf4'') to differentiated cells.<ref>{{cite journal| doi = 10.1038/nature05944| issn = 1476-4687| volume = 448| issue = 7151| pages = 318–324| last1 = Wernig| first1 = Marius| last2 = Meissner| first2 = Alexander| last3 = Foreman| first3 = Ruth| last4 = Brambrink| first4 = Tobias| last5 = Ku| first5 = Manching| last6 = Hochedlinger| first6 = Konrad| last7 = Bernstein| first7 = Bradley E.| last8 = Jaenisch| first8 = Rudolf| title = In vitro reprogramming of fibroblasts into a pluripotent ES-cell-like state| journal = Nature| date = 2007-07-19| pmid = 17554336| bibcode = 2007Natur.448..318W| s2cid = 4377572}}</ref> Utilizing the four genes previously listed, the differentiated cells are "reprogrammed" into pluripotent stem cells, allowing for the generation of pluripotent/embryonic stem cells without the embryo. The morphology and growth factors of these lab induced pluripotent cells, are equivalent to embryonic stem cells, leading these cells to be known as [[induced pluripotent stem cell]]s (iPS cells).<ref>{{Cite journal |last1=Takahashi |first1=Kazutoshi |last2=Yamanaka |first2=Shinya |date=2006-08-25 |title=Induction of Pluripotent Stem Cells from Mouse Embryonic and Adult Fibroblast Cultures by Defined Factors |journal=Cell |language=English |volume=126 |issue=4 |pages=663–676 |doi=10.1016/j.cell.2006.07.024 |issn=0092-8674 |pmid=16904174|s2cid=1565219 |doi-access=free |hdl=2433/159777 |hdl-access=free }}</ref> This observation was observed in mouse pluripotent stem cells, originally, but now can be performed in human adult [[fibroblast]]s using the same four genes. <ref>{{Cite journal |last1=Takahashi |first1=Kazutoshi |last2=Tanabe |first2=Koji |last3=Ohnuki |first3=Mari |last4=Narita |first4=Megumi |last5=Ichisaka |first5=Tomoko |last6=Tomoda |first6=Kiichiro |last7=Yamanaka |first7=Shinya |date=2007-11-30 |title=Induction of Pluripotent Stem Cells from Adult Human Fibroblasts by Defined Factors |journal=Cell |language=English |volume=131 |issue=5 |pages=861–872 |doi=10.1016/j.cell.2007.11.019 |issn=0092-8674 |pmid=18035408 |s2cid=8531539|doi-access=free |hdl=2433/49782 |hdl-access=free }}</ref>

Because ethical concerns regarding embryonic stem cells typically are about their derivation from terminated embryos, it is believed that reprogramming to these iPS cells may be less controversial. 

This may enable the generation of patient specific ES cell lines that could potentially be used for cell replacement therapies.  In addition, this will allow the generation of ES cell lines from patients with a variety of genetic diseases and will provide invaluable models to study those diseases.

However, as a first indication that the  iPS cell technology can in rapid succession lead to new cures, it was used by a research team headed by [[Rudolf Jaenisch]] of the [[Whitehead Institute for Biomedical Research]] in [[Cambridge, Massachusetts|Cambridge]], [[Massachusetts]], to cure mice of [[sickle cell anemia]], as reported by [[Science (journal)|''Science'' journal's]] online edition on December 6, 2007.<ref>{{cite news | url=https://www.washingtonpost.com/wp-dyn/content/article/2007/12/06/AR2007120602444.html | title=Scientists Cure Mice Of Sickle Cell Using Stem Cell Technique: New Approach Is From Skin, Not Embryos | author=Weiss, Rick | newspaper=[[The Washington Post]] | date=2007-12-07 | pages=A02 | access-date=2017-08-31 | archive-date=2018-12-25 | archive-url=https://web.archive.org/web/20181225160628/http://www.washingtonpost.com/wp-dyn/content/article/2007/12/06/AR2007120602444.html | url-status=live }}</ref><ref>{{cite journal|doi=10.1126/science.1152092|pmid=18063756|title=Treatment of Sickle Cell Anemia Mouse Model with iPS Cells Generated from Autologous Skin|journal=Science|volume=318|issue=5858|pages=1920–1923|year=2007|last1=Hanna|first1=J.|last2=Wernig|first2=M.|last3=Markoulaki|first3=S.|last4=Sun|first4=C.-W.|last5=Meissner|first5=A.|last6=Cassady|first6=J. P.|last7=Beard|first7=C.|last8=Brambrink|first8=T.|last9=Wu|first9=L.-C.|last10=Townes|first10=T. M.|last11=Jaenisch|first11=R.|bibcode=2007Sci...318.1920H|s2cid=657569}}</ref>

On January 16, 2008, a California-based company, Stemagen, announced that they had created the first mature cloned human embryos from single skin cells taken from adults. These embryos can be harvested for patient matching embryonic stem cells.<ref>{{cite news | url=http://news.bbc.co.uk/2/hi/science/nature/7194161.stm | title=US team makes embryo clone of men | author=Helen Briggs | publisher=[[BBC]] | date=2008-01-17 | pages=A01 | access-date=2008-01-18 | archive-date=2018-06-22 | archive-url=https://web.archive.org/web/20180622010307/http://news.bbc.co.uk/2/hi/science/nature/7194161.stm | url-status=live }}</ref>

===Contamination by reagents used in cell culture===
The online edition of ''Nature Medicine'' published a study on January 24, 2005, which stated that the human embryonic stem cells available for federally funded research are contaminated with non-human molecules from the culture medium used to grow the cells.<ref name=ebert>{{cite journal |last=Ebert |first=Jessica |date=24 January 2005 |title=Human stem cells trigger immune attack |journal=Nature News |publisher=[[Nature Publishing Group]] |location=London |url=http://cmbi.bjmu.edu.cn/news/0501/124.htm |doi=10.1038/news050124-1 |access-date=2009-02-27 |url-status=dead |archive-url=https://web.archive.org/web/20100924071349/http://cmbi.bjmu.edu.cn/news/0501/124.htm |archive-date=2010-09-24 |url-access=subscription }}</ref> It is a common technique to use mouse cells and other animal cells to maintain the pluripotency of actively dividing stem cells. The problem was discovered when non-human [[sialic acid]] in the growth medium was found to compromise the potential uses of the embryonic stem cells in humans, according to scientists at the [[University of California, San Diego]].<ref>{{cite journal |vauthors=Martin MJ, Muotri A, Gage F, Varki A |title=Human embryonic stem cells express an immunogenic nonhuman sialic acid |journal=Nat. Med. |volume=11 |issue=2 |pages=228–232 |year=2005 |pmid=15685172 |doi=10.1038/nm1181|s2cid=13739919 }}</ref>

However, a study published in the online edition of ''Lancet Medical Journal'' on March 8, 2005, detailed information about a new stem cell line that was derived from human embryos under completely cell- and serum-free conditions. After more than 6 months of undifferentiated proliferation, these cells demonstrated the potential to form derivatives of all three embryonic germ layers both ''in vitro'' and in [[teratoma]]s. These properties were also successfully maintained (for more than 30 passages) with the established stem cell lines.<ref>{{cite journal |vauthors=Klimanskaya I, Chung Y, Meisner L, Johnson J, West MD, Lanza R |title=Human embryonic stem cells derived without feeder cells |journal=Lancet |volume=365 |issue=9471 |pages=1636–1641 |year=2005 |pmid=15885296 |doi=10.1016/S0140-6736(05)66473-2|s2cid=17139951 }}</ref>

===Muse cells===
{{main|Muse cell}}

Muse cells (Multi-lineage differentiating stress enduring cell) are [[Carcinogenesis|non-cancerous]] [[pluripotent stem cell]] found in adults.<ref name="Kuroda">{{cite journal |doi=10.1073/pnas.0911647107 |pmid=20421459 |pmc=2889306 |title=Unique multipotent cells in adult human mesenchymal cell populations |journal=Proceedings of the National Academy of Sciences |volume=107 |issue=19 |pages=8639–8643 |year=2010 |last1=Kuroda |first1=Y. |last2=Kitada |first2=M. |last3=Wakao |first3=S. |last4=Nishikawa |first4=K. |last5=Tanimura |first5=Y. |last6=Makinoshima |first6=H. |last7=Goda |first7=M. |last8=Akashi |first8=H. |last9=Inutsuka |first9=A. |last10=Niwa |first10=A. |last11=Shigemoto |first11=T. |last12=Nabeshima |first12=Y. |last13=Nakahata |first13=T. |last14=Nabeshima |first14=Y.-i. |last15=Fujiyoshi |first15=Y. |last16=Dezawa |first16=M. |bibcode=2010PNAS..107.8639K |doi-access=free }}</ref><ref>{{Cite book|url=https://www.springer.com/us/book/9784431568452|title=Muse Cells &#124; SpringerLink|access-date=2022-01-13|archive-date=2019-02-19|archive-url=https://web.archive.org/web/20190219130237/https://www.springer.com/us/book/9784431568452|url-status=live}}</ref> They were discovered in 2010 by Mari Dezawa and her research group.<ref name="Kuroda" /> Muse cells reside in the connective tissue of nearly every organ including the umbilical cord, bone marrow and peripheral blood.<ref>Zikuan Leng 1 2, Dongming Sun 2, Zihao Huang 3, Iman Tadmori 2, Ning Chiang 2, Nikhit Kethidi 2, Ahmed Sabra 2, Yoshihiro Kushida 4, Yu-Show Fu 3, Mari Dezawa 4, Xijing He 1, Wise Young 2Quantitative Analysis of SSEA3+ Cells from Human Umbilical Cord after Magnetic SortingCell Transplant
. 2019 Jul;28(7):907–923.</ref><ref name="Kuroda" /><ref name="WakaoPNAS">{{cite journal |doi=10.1073/pnas.1100816108 |pmid=21628574 |pmc=3116385 |title=Multilineage-differentiating stress-enduring (Muse) cells are a primary source of induced pluripotent stem cells in human fibroblasts |journal=Proceedings of the National Academy of Sciences |volume=108 |issue=24 |pages=9875–9880 |year=2011 |last1=Wakao |first1=S. |last2=Kitada |first2=M. |last3=Kuroda |first3=Y. |last4=Shigemoto |first4=T. |last5=Matsuse |first5=D. |last6=Akashi |first6=H. |last7=Tanimura |first7=Y. |last8=Tsuchiyama |first8=K. |last9=Kikuchi |first9=T. |last10=Goda |first10=M. |last11=Nakahata |first11=T. |last12=Fujiyoshi |first12=Y. |last13=Dezawa |first13=M. |bibcode=2011PNAS..108.9875W |doi-access=free }}</ref><ref name=":3">{{cite journal |doi=10.3727/096368916X690881 |pmid=26884346 |title=Muse Cells Provide the Pluripotency of Mesenchymal Stem Cells: Direct Contribution of Muse Cells to Tissue Regeneration |journal=Cell Transplantation |volume=25 |issue=5 |pages=849–861 |year=2016 |last1=Dezawa |first1=Mari |doi-access=free }}</ref><ref name=":4">{{cite journal |doi=10.1016/j.jstrokecerebrovasdis.2015.12.033 |pmid=27019988 |title=Mobilization of Pluripotent Multilineage-Differentiating Stress-Enduring Cells in Ischemic Stroke |journal=Journal of Stroke and Cerebrovascular Diseases |volume=25 |issue=6 |pages=1473–1481 |year=2016 |last1=Hori |first1=Emiko |last2=Hayakawa |first2=Yumiko |last3=Hayashi |first3=Tomohide |last4=Hori |first4=Satoshi |last5=Okamoto |first5=Soushi |last6=Shibata |first6=Takashi |last7=Kubo |first7=Michiya |last8=Horie |first8=Yukio |last9=Sasahara |first9=Masakiyo |last10=Kuroda |first10=Satoshi }}</ref> They are collectable from commercially obtainable mesenchymal cells such as human [[fibroblast]]s, bone marrow-mesenchymal stem cells and adipose-derived stem cells.<ref name=KurodaNature>{{cite journal |doi=10.1038/nprot.2013.076 |pmid=23787896 |title=Isolation, culture and evaluation of multilineage-differentiating stress-enduring (Muse) cells |journal=Nature Protocols |volume=8 |issue=7 |pages=1391–1415 |year=2013 |last1=Kuroda |first1=Yasumasa |last2=Wakao |first2=Shohei |last3=Kitada |first3=Masaaki |last4=Murakami |first4=Toru |last5=Nojima |first5=Makoto |last6=Dezawa |first6=Mari |s2cid=28597290 }}{{medrs|date=November 2013}}</ref><ref name=":5">{{cite journal |doi=10.1089/scd.2013.0473 |pmid=24256547 |title=Human Adipose Tissue Possesses a Unique Population of Pluripotent Stem Cells with Nontumorigenic and Low Telomerase Activities: Potential Implications in Regenerative Medicine |journal=Stem Cells and Development |volume=23 |issue=7 |pages=717–728 |year=2014 |last1=Ogura |first1=Fumitaka |last2=Wakao |first2=Shohei |last3=Kuroda |first3=Yasumasa |last4=Tsuchiyama |first4=Kenichiro |last5=Bagheri |first5=Mozhdeh |last6=Heneidi |first6=Saleh |last7=Chazenbalk |first7=Gregorio |last8=Aiba |first8=Setsuya |last9=Dezawa |first9=Mari }}</ref><ref name="Heneidi">{{cite journal |doi=10.1371/journal.pone.0064752 |pmid=23755141 |pmc=3673968 |title=Awakened by Cellular Stress: Isolation and Characterization of a Novel Population of Pluripotent Stem Cells Derived from Human Adipose Tissue |journal=PLOS ONE |volume=8 |issue=6 |pages=e64752 |year=2013 |last1=Heneidi |first1=Saleh |last2=Simerman |first2=Ariel A. |last3=Keller |first3=Erica |last4=Singh |first4=Prapti |last5=Li |first5=Xinmin |last6=Dumesic |first6=Daniel A. |last7=Chazenbalk |first7=Gregorio |bibcode=2013PLoSO...864752H |doi-access=free }}</ref> Muse cells are able to generate cells representative of all three germ layers from a single cell both spontaneously and under [[cytokine]] induction. Expression of pluripotency genes and triploblastic differentiation are self-renewable over generations. Muse cells do not undergo [[teratoma]] formation when transplanted into a host environment in vivo, eradicating the risk of [[tumorigenesis]] through unbridled cell proliferation.<ref name="Kuroda" />