Stemolecule SB431542 in Solution, 5 mg (10 mM). SB431542 is an inhibitor of the transforming growth factor-beta 1 (TGF-b1) activin receptor-like kinases (ALKs). It is a selective and potent inhibitor of ALK-4, -5 and -7. SB431542 inhibits endogenous activin and TGF-b signaling without affecting more divergent BMP signaling utilizing ALK-1, -2, -3, and -61,2. SB431542 stimulates proliferation, differentiation, and sheet formation of endothelial cells derived from embryonic stem cells. Chemical name: 4-[4-(1,3-benzodioxol-5-yl)-5-pyridin-2-yl-1H-imidazol-2-yl]benzamide. 301836-41-9.