LDN193189 is a highly potent small molecule BMP inhibitor; inhibiting BMP type I receptors ALK2 (IC50: 5 nM), ALK3 (IC50: 30 nM) and ALK6 (TGFβ1/BMP signaling) and subsequent SMAD phosphorylation; LDN193189 is useful tool in stem cell biology. LDN193189 shows significant in vivo clinical utility, inhibiting FOP and ectopic ossification and a potential agent in the treatment of NSCLC lung tumors.