JAK2 and acquired polycythemia vera: However, BCR-ABL translocation was present in few CFU-GM colonies and absent in CFU-E.6 In 2 patients with PV and CML32 and a patient with PMF and CML,23 all hematopoietic colonies had JAK2, some had both JAK2 and BCR-ABL, and none had BCR-ABL alone.