Thus, the present study identified protective associations of HLA class II alleles with Japanese SSc; our findings support independent protective roles for the four class II alleles, DRB1*13:02, DRB1*14:06, DQB1*03:01, and DPB1*02:01, in the pathogenesis of SSc. The gene discussed is HLA-DRB1; the disease is systemic sclerosis.