Alongside the HLA susceptibility studies, other research has uncovered associations between PV and autoantigen or immune gene sequences: specific Dsg3 haplotypes were significantly linked with PV in both British and Indian cohorts (Capon et al., 2006); while single nucleotide polymorphisms within the variable region of the immunoglobulin heavy chain VH3 gene were associated with PF in two patients (Yamagami et al., 2009). This evidence concerns the gene DSG3 and acquired polycythemia vera.