Dsg1 granules extended through the entire Malpighian layer over the floor of the PF acantholytic bulla, confirming the internalization of Dsg1 described thirty years ago.25, 26, 27, 28 The internalization of Dsg3 in the LS sample of the PV group was less evident but has been commonly described.29, 30, 31, 32 While Dsg2 was overexpressed in IS, its internalization was absent in LS samples of the PF and PV groups, representing further evidence that anti-Dsg2 antibodies have no pathogenic role in pemphigus acantholytic process. The gene discussed is DSG1; the disease is acquired polycythemia vera.