HLA-DQA1 and systemic sclerosis: According to the results of the study, there was a strong disease-risk association of HLA DPB1*13:01 in the diffuse type of SSc, whereas a protective effect was shown with regard to HLA-DRB1*07:01, HLA-DQA1*02:01, HLA-DQB1*02:02, HLA-DRB4*01:01 HLA-B*44:03, and HLA-C*16:01.