Table 2.

Reprogramming factor replacements

Original reprogramming factor(s)	Substitute factor	Proposed mechanism	References
cMyc	nMyc or LMyc	Homologues that may be redundant in function. LMyc has lower transformation activity compared with cMyc.	Nakagawa et al. 2003, 2010
	Wnt3a	c-Myc is a target of Wnt signaling.	Marson et al. 2008
	miR-291-3p, -294, or-295	miR290 cluster is a c-Myc target.	Judson et al. 2009
Klf4	Klf1, Klf2, or Klf5	Homologues that may be redundant in function.	Nakagawa et al. 2008
	Esrrb or Esrrg	Esrrb regulates Klf4 expression, has similar binding targets as Oct4, Sox2, and Klf4, and forms a protein complex with Qct4.	Feng et al. 2009a, van den Berg et al. 2008, Chen et al. 2008
Sox2	Sox1, Sox3, Sox15, or Sox18	Homologues that may be redundant in function.	Nakagawa et al. 2008
	Nanog	Nanog has similar binding targets as Sox2.	Ichida et al. 2009
Sox2 and c-Myc	Smad7	Inhibits Tgfβ signaling, promoting MET.	Li et al, 2010, Maherali and Hochedlinger 2009, Ichida et al. 2009
Oct4	Nr5a1 or Nr5a2	Binds enhancer and promoter of Oct4 and regulates its expression.	Heng et al. 2010

Listed are RNAs and proteins that are able to replace individual reprogramming factors. For a comprehensive review of small molecule replacers of reprogramming, see Feng et al. 2009.