By inhibiting the activin receptor type-1(ACVR1) and reducing hepcidin, momelotinib increases iron availabilityand thereby ameliorates anemia.18 Thereare also several JAK2 inhibitors (JAKinibs) that are or have beenin late-stage clinical trials for hematological diseases (MPN, leukemia,multiple myeloma, and lymphoma): lestaurtinib, itacitinib, ilginatinib,gandotinib, cerdulatinib, and AT9283. Here, ACVR1 is linked to plasma cell myeloma.