Strikingly, the previous study reported that a high concentration of polyamines was detected in blood plasma from PV patients [44], and this supports our working hypothesis that the c-Myc-ODC axis seems to play a critical role in episodes of PV. However, since this previous research was reported before the discovery of JAK2 mutation (V617F) in patients with MPNs, the relationship between polyamine production and JAK2 (V617F) has not been addressed. Here, JAK2 is linked to acquired polycythemia vera.