Selective inhibitor of TGF-β type-I receptor (TGF-β RI, TGFR-I, TβR-I, ALK-5) (IC50 values are 59, 400 and 1400 nM for TGR-β RI, TGF-β RII and MLK-7K respectively). Inhibits TGF-β-dependent luciferase production in mink lung cells (p3TP lux) and growth in mouse fibroblasts (NIH 3T3) (IC50 values are 47 and 89 nM respectively). Suppresses invasion of MDA-MB-231 breast cancer cells in a matrigel invasion assay.