Relevant to this, this study is the first to show a GWS association of HLA-DRB1*15:01 with ATA + relative to ATA − SSc (OR = 2.4, p = 4.3 × 10−8), following the recently published association of this allele with ATA + SSc by case-control analysis (Acosta-Herrera et al., 2021), suggesting commonalities in the preferential binding of this and other ATA + SSc associated HLA-DRB1 alleles to TOP1 derived peptides. This evidence concerns the gene HLA-DRB1 and systemic sclerosis.