Given that the activation of the JAK-STAT pathway is contingent upon the phosphorylation status of JAK and STAT proteins, and considering that cytokines implicated in PV primarily operate through STAT3 and STAT6, we assessed the levels of phosphorylated STAT3 and STAT6 in the skin lesions of PV patients and healthy controls. This evidence concerns the gene STAT6 and acquired polycythemia vera.