Imatinib blocked angiogenic pathways in vascular mural cells. (A) Effect of imatinib on VEGF secretion from VSMCs at 3, 24, and 48 hours after treatment. (B) Effect of imatinib on TGF-β secretion from VSMCs and cardiac microvascular endothelial cells (CMECs) at 48 hours after treatment. (C) Effect of imatinib on PDGF-BB–induced phosphorylation of PDGFRα, PDGFRβ, c-Kit, c-Abl, AKT, and ERK1/2 by immunoblot of VSMCs and pericytes in culture.