SB505124是一种选择性TGFβR抑制剂，作用于ALK4和ALK5，无细胞试验中IC50分别为129 nM和47 nM，也抑制ALK7，但不抑制ALK1，2，3或6。An inhibitor of Activin receptor-like kinase 5 SB505124 is a selective inhibitor of TGFβR for ALK4, ALK5 with IC50 of 129 nM and 47 nM in cell-free assays, respectively, also inhibits ALK7, but does not inhibit ALK1, 2, 3, or 6. An inhibitor of Activin receptor-like kinase 5