While examining HLA region by imputing through genome-wide SNP data, Raychaudhuri and others found SNP variants corresponding to five amino acids including three in HLA-DRβ1 and one in each HLA-B (at position 9) and HLA-DPβ1 almost completely explain the MHC association to seropositive RA risk [28]. The gene discussed is HLA-DRB1; the disease is rheumatoid arthritis.