Selective inhibitor of bone morphogenic protein (BMP) type-I receptor activin receptor-like kinase 2 (ALK2) receptor (IC50 = 108 nM [Hao et al., 2010] or 12.6 nM [Mohedas et al., 2013] in in vitro kinase assays). Exhibits 6- and 19-fold selectivity for ALK-2 over ALK-1 and ALK-3, respectively, and no significant inhibition of AMPK, ALK5, KDR (VEGFR-2) or PDGFRβ receptors. Blocks BMP4-induced phosphorylation of Smads 1, 5 and 8 in HEK293 cells. Promotes neurogenesis in human induced pluripotent stem cells (iPSCs) when used in combination with SB 431542 (Cat. No. 1614). Purity 98%. MW (observed): 380.44