ACVR1 and neoplasm: The ACVR1 mutation found in 20% of patient has also been an area of preclinical investigation, with ALK2 inhibitors demonstrating modest preclinical efficacy and an ability to cross the blood-brain barrier [17, 26], and the BMP inhibitor noggin and ACVR1 inhibitor LDN212854 both improving overall survival and reducing tumor proliferation in mice with generated PDGAF./HK3.3/ACVR mutant tumors [17].