Momelotinib acts by inhibiting the hyperactivated BMP6/ACVR1/SMAD pathway and suppressing hepcidin expression; thus, treatment with momelotinib results in higher circulating iron and Hb levels and improved erythropoiesis [28], which leads to significant anemia benefits in MF patients [81]. This evidence concerns the gene ACVR1 and anemia (phenotype).