JAK2 and acquired polycythemia vera: In contrast to highly transforming potential of BCR-ABL, the long latency of chronic indolent phase of JAK2 V617F-positive MPN (with PV being a good example), where the frequency of transformation is relatively low, supports a model in which PV progenitors avoid detrimental effects of oncogenic and oxidative stress and rather utilize signaling adaptations to extrinsic and intrinsic stresses to prevent accumulation of DNA damage.