<h4>Introduction</h4>Pemphigus vulgaris (PV) is a potentially life-threatening autoimmune blistering disease characterized by autoantibodies directed against the desmosomal cadherins desmoglein 3 (DSG3) and desmoglein 1 (DSG1), which are essential for keratinocyte adhesion. Here, DSG1 is linked to acquired polycythemia vera.