The V617F JAK2 mutation is uncommon in cancers and in myeloid malignancies other than the classic myeloproliferative disorders

Four groups recently reported the existence of an activating mutation of JAK2 in many patients with one of the classic myeloproliferative disorders (MPDs).[1][1]-[4][2] Mutant Janus kinase 2 (JAK2) has increased kinase activity, renders BaF3 cells cytokine independent, and produces erythrocytosis in