FOXO1, FOXO3 and FOXO4 stimulate transcription from the CDKN1A gene promoter. In response to TGF-beta signaling, FOXO transcription factors may cooperate with the active SMAD2/3:SMAD4 complexes to upregulate CDKN1A transcription (Seoane et al. 2004). FOXO1-mediated induction of CDKN1A gene transcription is implicated in CDKN1A upregulation in liver cells during fasting (Tinkum et al. 2013). Acetylation of FOXO4 by EP300 (p300) or CREBBP (CBP) in response to oxidative stress does not affect FOXO4-mediated induction of CDKN1A gene transcription (Dansen et al. 2009).