Of the remaining 11/42 (26.2%) cases, 7/42 (16.7%) displayed PMF-like morphology but lacked any of the minor diagnostic criteria, while 4/42 (9.5%) were morphologically consistent with PV, but failed to meet the required Hb threshold values (3 cases) or lacked JAK2 mutations [35]. This evidence concerns the gene JAK2 and acquired polycythemia vera.