One relates to the presence of SLE-associated SNPs in strong linkage disequilibrium with HLA-DRB1∗15:01 present in the intergenic XL9 region, located between HLA-DRB1 and HLA-DQA1, resulting in increased surface expression of these genes in HLA-DR2h carriers [41,42]. Here, HLA-DQA1 is linked to systemic lupus erythematosus.