HLA-DRB1*15 was significantly more often seen in MS patients (CIS + RRMS + PPMS) compared to HC (p = 2.8 × 10−5, Odds ratio (OR) = 10.58, 2.82–67.99 95% confidence interval (CI)), confirming the association between the disease and this allele. This evidence concerns the gene HLA-DRB1 and in situ carcinoma.