DRB1*01∶01, DRB1*15∶02, DRB1*16∶02 were significantly associated with SSc at p-values <10−4, while DRB1*04∶06, DRB1*12∶02 and DRB1*07∶01 were strongly associated with SSc achieving the p-values of 0.0001, 0.0014 and 0.0021, respectively (Table 3). This evidence concerns the gene HLA-DRB1 and systemic sclerosis.