LDN-193189 (DM3189) 2HCl is a selective BMP signaling inhibitor, inhibits the ALK1, ALK2, ALK3 and ALK6 with IC50s of 0.8 nM, 0.8 nM, 5.3 nM and 16.7 nM in the kinase assay, respectively. LDN-193189 inhibits the transcriptional activity of the BMP type I receptors ALK2 and ALK3 with IC50s of 5 nM and 30 nM in C2C12 cells, respectively, exhibits 200-fold selectivity for BMP versus TGF-β.