Recently orally administered small molecule inhibitors of ACVR1/ALK2 [92] were tested in phase 1 studies on healthy individuals (KER-047 [93], BCX9250 [94]) and phase 2 studies in FOP patients (IPN60130 (FALKON) [95], INCB000928 (PROGRESS) [96]). Here, ACVR1 is linked to fibrodysplasia ossificans progressiva.