D4476 (Casein Kinase I Inhibitor, D 4476, D-4476) is a potent, selective ATP-competitive inhibitor of CK1 with IC50 of 0.3 uM in vitro.
D4476 slightly weaker for ALK5 inhibition (IC50=0.5 uM); weak activity for p38α MAPK and no activity for PKB, SGK.
D4476 specifically inhibits the phosphorylation of endogenous FOXO1a on Ser322 and Ser325.
D4476 more potent and specific than IC261 or CKI-7.
