Editing Embryonic stem cell (section)

=== Self renewal and repair of structure  ===

Under defined conditions, embryonic stem cells are capable of self-renewing indefinitely in an undifferentiated state. Self-renewal conditions must prevent the cells from clumping and maintain an environment that supports an unspecialized state.<ref>{{cite journal |author=Ying |title=BMP Induction of Id Proteins Suppresses Differentiation and Sustains Embryonic Stem Cell Self-Renewal in Collaboration with STAT3 |journal=Cell |volume=115 |issue= 3|pages= 281–292 |year=2003 |pmid= 14636556|doi=10.1016/S0092-8674(03)00847-X |last2=Nichols |first2=J |last3=Chambers |first3=I |last4=Smith |first4=A|s2cid=7201396 |doi-access=free }}</ref> Typically this is done in the lab with media containing [[fetal bovine serum|serum]] and [[leukemia inhibitory factor]] or serum-free media supplements with two inhibitory drugs ("2i"), the [[MEK inhibitor]] PD03259010 and [[GSK-3 inhibitor]] CHIR99021.<ref>{{cite journal|pmid=25288119|year=2014|last1=Martello|first1=G.|title=The nature of embryonic stem cells|journal=Annual Review of Cell and Developmental Biology|volume=30|pages=647–75|last2=Smith|first2=A.|doi=10.1146/annurev-cellbio-100913-013116|doi-access=free}}</ref>