Typically, the cutaneous mucocutaneous type of PV can be detected as positive for both anti-Dsg3 and anti-Dsg1 antibodies, the mucocutaneous-dominant type of PV can be detected as positive for anti-Dsg3 antibodies only, while only anti-Dsg1 antibodies can be detected as positive in PF (3). The gene discussed is DSG1; the disease is acquired polycythemia vera.