The expression of STAT6 protein was significantly higher in PV (p = 0.04), BP (p = 0.02) and LP patients (p = 0.05) as compared to the C. There was no statistical difference in expression of STAT6 in CUS patients (p < 0.49) as compared to the C (Figure 2 and Table 3). This evidence concerns the gene STAT6 and acquired polycythemia vera.