MYC and acquired polycythemia vera: Our results revealed a transient, low-level caspase-3 activation downstream of disrupted Dsg3 cis- or trans-adhesion [21,22], which occurs early in PV acantholysis, is uncoupled from apoptosis or classical apoptotic pathways and, as judged from caspase-3 inhibitor treatments, contributes to major events in PV pathogenesis; these are increased expression of proliferation markers including Myc family members, p38MAPK activation, cleavage of Dsg3, keratin retraction as well as loss of intercellular adhesion.