ACVR1 and anemia: First, inhibition of BMP/SMAD signaling by the BMPR1 (ALK2/ALK3/ALK6) inhibitor dorsomorphin and its derivate LDN-193189 as well as the human recombinant BMP ligand antagonist ALK3-Fc and the soluble hemojuvelin-Fc (HJV-Fc) were shown to reduce hepcidin expression in animal models of AI thus stimulating mobilization of iron from tissue stores and resolving anemia [164,302,303,304,305].