The remaining MPN cases (n = 24/231, 10.4%) were BCR-ABL negative, the majority of whom were polycythemia vera (PV), which was identified in 11 cases (4.7%), followed by PMF (n = 7, 3%) and ET (n = 6, 2.6%) cases.4 The gene discussed is ABL1; the disease is acquired polycythemia vera.