An inhibitor of PDGFRβ, VEGFR2, and FGFR1 (IC50 = 0.06, 2.4, and 3.0 μM, respectively) but not EGFR (IC50 >100 μM); suppresses tumor growth, blocks angiogenesis in tumors, and induces apoptosis of tumor vasculature and regression of established tumors; also inhibits Aurora kinases B and C (IC50 = 35 and 210 nM, respectively) and may target other kinases