NPPB and acquired polycythemia vera: Notably, in the high-PV group, we observed a significant reduction in plasma BNP levels (p = 0.016), whereas the low-PV group exhibited no notable change in plasma BNP levels (p = 0.23), as depicted in Figure 2A. Although the decline in plasma BNP levels appeared to be more pronounced in the high-PV group compared to the low-PV group, this disparity did not reach statistical significance (p = 0.15; Figure 2B).