A potent inhibitor of PDGFRβ (IC50 = 10 nM); inhibits VEGFR2 (IC50 = 140 nM); selectively inhibits PDGF- over VEFG-, FGF-, and EGF-induced cell proliferation (IC50s = 0.11, 10, 10, and 21.9 μM, respectively); accelerates downregulation of fibroblast genes and increases the yield of beating clusters in HFFs treated with 15 compounds to induce a cardiac myocyte-like phenotype