Mice receiving BM cells ectopically expressing JAK2-V617F + L902Q develop an MPN with increased hematocrit (HCT), Hemoglobin (HGB), reticulocytes, white blood cell (WBC), and RBC in the peripheral blood, similar to mice receiving JAK2-V617F transduced BM (Fig. 2A-C, Supplementary Fig. 7A, B). The gene discussed is JAK2; the disease is myeloproliferative disorder.