These data, taken together with the data on anti-TPO distribution based on HLA type, suggest that while anti-Dsg3 antibodies can be generated by a majority of PV patients regardless of HLA type; anti-TPO, and perhaps anti-Tg antibodies are preferably generated in PV patients that do not carry the classical PV-susceptibility alleles DRB1*0402 and DQB1*0503 and may be more relevant than anti-Dsg1 antibodies in this subpopulation. This evidence concerns the gene TG and acquired polycythemia vera.