A protective effect of the HLA-A*02 allele, independent from the HLA-DRB1*15∶01 allele, has been established by several studies [4], [20]-[22]; in addition to the effect of the HLA-A and HLA-DRB1 loci, also the HLA-B*12 allele has been suggested to influence MS risk [22]. This evidence concerns the gene HLA-DRB1 and myeloid sarcoma.