A further deficiency of IFN-γ(Th1) and TGF-β is correlated with enhanced IL-6 and IL-17(Th17), which supports Timoteo et al. that in PV there is a relative dearth of Th1 and Treg cells as compared to th17 cell subsets [30]. Here, TGFB1 is linked to acquired polycythemia vera.