Polycythemia vera (PV), one of the chronic myeloproliferative neoplasms, is a clonal hematopoietic stem cell disorder driven by EPO hypersensitive signaling via the JAK2-STAT5 pathway, resulting in excess proliferation of erythroid precursors (Rampal et al., 2014; Levine et al., 2005; Baxter et al., 2005; Kralovics et al., 2005; James et al., 2005; Lu et al., 2008; Akada et al., 2010). Here, JAK2 is linked to acquired polycythemia vera.