DSG3 and acquired polycythemia vera: It was not until 2003 that Olivry and colleagues, by means of immunofluorescence, immunoblotting and immunoprecipitation, detected the presence of anti-keratinocyte AA in the serum (Fig. 2) and lesional skin of dogs with PV and documented for the first time that DSG3 was also the major canine PV antigen [46].