Editing Exogeny (section)

=== Biology ===
An exogenous [[contrast agent]], in [[medical imaging]] for example, is a liquid injected into the patient [[intravenously]] that enhances visibility of a pathology, such as a [[tumor]]. An exogenous factor is any material that is present and active in an individual [[organism]] or living [[cell (biology)|cell]] but that originated outside that organism, as opposed to an endogenous factor.

In the origins of [[disease]]s, exogenous factors, namely those that are factors in [[inflammation]] or [[Stress (biology)|stress]] (such as [[overexertion]], [[overeating]], and extreme feelings of emotions of grief or anger), all contribute to exhaustion or modifications in [[gene]]s.<ref>{{Cite journal |last1=Sornette |first1=Didier |last2=Yukalov |first2=V.I. |last3=Yukalova |first3=E.P. |last4=Henry |first4=J.-Y |last5=Schwab |first5=David J. |last6=Cobb |first6=J.P. |year=2009 |title=Endogenous versus Exogenous Origins of Diseases |url=https://doi.org/10.1142/S0218339009002880 |journal=[[Journal of Biological Systems]] |volume=17 |issue=2 |pages=225–267 |arxiv=0710.3859 |doi=10.1142/S0218339009002880 |via=[[World Scientific]] |s2cid=10818515}}</ref> An accumulation of such stressors affect the [[immune system]] by disrupting the amount of communication that occurs between the immune system and other areas of the body.

[[DNA]] introduced to cells via [[transfection]] or [[viral transduction]] is an exogenous factor. Exogenous factors in DNA, particularly [[DNA damage]], are more known as environmental factors that cause progression in the impairment of DNA.<ref>{{Cite journal |last1=Friedberg |first1=Errol C. |last2=McDaniel |first2=Lisa D. |last3=Schultz |first3=Roger A. |date=February 2004 |title=The role of endogenous and exogenous DNA damage and mutagenesis |url=https://doi.org/10.1016/j.gde.2003.11.001 |journal=[[Current Opinion (Elsevier)|Current Opinion in Genetics & Development]] |volume=14, 1 |issue=1 |pages=5–10 |doi=10.1016/j.gde.2003.11.001 |pmid=15108798 |via=[[Elsevier]] [[Science Direct]]|url-access=subscription }}</ref> Such exogenous factors would be different chemical agents, [[ionizing radiation]] (IR), and [[ultraviolet radiation]] (UV). These factors penetrate the deeper layers of the cell, causing great damage, with either [[apoptosis]] or senescence occurring, further leading to [[Arrested development|arrested]] or altered development and aging of the organism causing [[neurological disorder]]s and [[cancer]].<ref>{{Cite journal |last=Hakem |first=Razqallah |date=January 16, 2008 |title=DNA-damage repair; the good, the bad, and the ugly |journal=[[The EMBO Journal]] |volume=27 |issue=4 |pages=589–605 |doi=10.1038/emboj.2008.15 |pmc=2262034 |pmid=18285820}}</ref>