DSG3 and acquired polycythemia vera: To validate the immunohistochemical findings, we studied two immortalized keratinocyte cell lines N/TERT (skin-derived) and OKF4 (oral-derived) treated with PV sera (including 10 patients) with their pathogenicity towards Dsg3 depletion characterized previously (37), alongside with AK23, a mouse monoclonal antibody (mAb) against Dsg3 (7).