ACVR1 and fibrodysplasia ossificans progressiva: It has been shown that ALK2 R206H knock-inmice develop a phenotype that is characteristic for FOP, includinggreat toe malformation and heterotopic ossification, which indicatesthat the ALK2 R206H mutation drives the development of FOP.35 To date, a large number of clinical trials targetingDMG with radiotherapy, biologics, chemotherapeutics and their combinationshave failed.36,37 This indicates that there isa clear demand for an innovative therapeutic approach such as theutilization of small molecules with a novel mechanism of action.38,39