An inhibitor of Chk1 and WEE1 (IC50s = 47 and 97 nM, respectively); selective for Chk1 and WEE1 over PKC (IC50 = 3.4 μM) and Cdk4 (IC50 = 3.75 μM); selective for Chk1 and WEE1 over c-Src and the PDGF and FGF receptors (IC50s = >50 μM for all), and other Cdks (IC50s = >50 μM); sensitizes SK-OV-3 and OVCAR-3 ovarian cancer cells, as well as cisplatin-resistant A2780cis cells, to cisplatin at 0.5 μM; induces myoblast differentiation into mature osteoblasts and hESC differentiation into cells with mesoderm or cytotrophoblast stem cell lineages when used in combination with BMP4