CKI-7 free base is a potent and ATP-competitive inhibitor of casein kinase 1 (CK1; IC50: 6 μM; Ki: 8.5 μM) and a selective Cdc7 kinase inhibitor. CKI-7 free base also inhibits SGK, ribosomal S6 kinase-1 (S6K1), and MSK1.
MRT00033659 is an effective broad-spectrum kinase inhibitor of CK1 (IC50=0.9 µM for CK1δ) and CHK1 (IC50=0.23 µM). MRT00033659 is a pyrazolo-pyridine analogue. It also induces p53 pathway activation and E2F-1 destabilization.