LDN193189 is a potent selective BMP type I receptor (BMP I) inhibitor. LDN-193189 efficiently inhibits transcriptional activity of the BMP type I receptors ALK2 and ALK3 with IC50 values of 5 nM and 30 nM, respectively. LDN-193189 can be used for the research of bone morphogenetic protein signalling, such as fibrodysplasia ossificans progressiva[1][2][3].