Moreover, previous studies have reported that dorsomorphin could block EndMT induced by BMP‐4 in patients with FOP due to the ability of inhibiting ALK‐2/Smad signalling pathway9, 10 suggesting that the BMP/ALK‐2/Smad signalling pathway may play a crucial role in HO formation. The gene discussed is ACVR1; the disease is fibrodysplasia ossificans progressiva.