Studies in Han Chinese patients with PV have highlighted DRB1*04, DRB1*14 and DQB1*05:03 as relevant risk alleles (Zhou et al., 2003; Geng et al., 2005; Liu et al., 2008; Gao et al., 2018), as well as HLA-DRB1*03 and HLA-CW*14 in the same Chinese population with PNP (Martel et al., 2003; Liu et al., 2008). This evidence concerns the gene HLA-DRB1 and acquired polycythemia vera.