Members of this family of proteins act as negative regulators of G1 to S cell cycle phase progression by inhibiting cyclin-dependent kinases. Inhibitory effects are additive with GADD45 proteins but occur also in the absence of GADD45 proteins. Furthermore, they act as a repressor of the orphan nuclear receptor NR4A1 by inhibiting AB domain-mediated transcriptional activity [1].

1: CR6-interacting factor 1 interacts with Gadd45 family proteins and modulates the cell cycle. Chung HK, Yi YW, Jung NC, Kim D, Suh JM, Kim H, Park KC, Song JH, Kim DW, Hwang ES, Yoon SH, Bae YS, Kim JM, Bae I, Shong M; J Biol Chem. 2003;278:28079-28088. PMID:12716909