HLA-DPB1 and systemic sclerosis: On the other hand, a previously reported SSc-associated HLA-DQB1*03:01 in US population [7] was found to coexist with HLA-DPB1*13:01 in associated with SSc in this Chinese population (12.06% in SSc patients vs. 2.2% in controls, p = 0.0045, OR = 3.98, 95% CI = 1.34–12.54).