The combination of three risk alleles in the DPA1/DPB1 locus, CAC (ATA+ P  =  1.27×10−76, OR = 8.84 [6.72–11.63]) of the SNPs rs987870, rs3135021 and rs6901221 respectively was present in 10.6% of the ATA positive SSc patients compared to only 1.3% of the controls (Table 3). Here, HLA-DPA1 is linked to systemic sclerosis.