Inhibitor of DNA Binding Protein 2 (ID2)

ID2 belongs to the inhibitor of DNA binding (ID) family, members of which are transcriptional regulators that contain a helix-loop-helix (HLH) domain but not a basic domain.

ID2 is able to disrupt the antiproliferative effects of tumor suppressor proteins of the RB family, thus allowing cell cycle progression. This protein may play a role in negatively regulating cell differentiation. A pseudogene has been identified for this gene.This function correlates with the ability of ID2 to associate physically with active, hypophosphorylated forms of the pocket proteins in vitro and in vivo. By inactivating RB, ID2 is also able to abolish the function of another growth inhibitory protein, p16, that operates upstream to RB.