EW-7197 is a potent inhibitor of activin receptor-like kinase 5 (ALK5, also known as TGF-β receptor type 1; IC50 = 12.9 nM). It also inhibits ALK2 and ALK4 at nanomolar concentrations. EW-7197 blocks TGF-β/Smad signaling, cell migration, invasion, and lung metastasis in mouse mammary tumor virus/c-Neu mice and 4TI orthotopic-grafted mice. It also inhibits epithelial-to-mesenchymal transition (EMT) in TGF-β-treated breast cancer cells.2 EW-7197 is used to block TGF-β signaling and EMT in animal models of cancer and fibrosis.