In univariate analysis, we found that high mRNA expressions of HLA-DPB2 [hazard ratio (HR) = 0.74, 95% CI: 0.60–0.92, and P = 0.006] and HLA-DPB1 (HR = 0.995, 95% CI: 0.9918–0.9988, and P = 0.009) were related to longer OS of BC patients (Supplementary Table 3). This evidence concerns the gene HLA-DPB2 and breast cancer.