In PV, the multivariate analysis showed that previous arterial events, hyperlipidemia and hypertension predicted subsequent arterial thrombotic events; previous venous events, leukocyte counts ≥ 11 × 109/L, and major bleeding were predictors of subsequent venous events; and TET2 or ASXL1 mutations had no effect on arterial or venous thrombosis [36]. This evidence concerns the gene TET2 and acquired polycythemia vera.