HLA-DPB1 and type 1 diabetes mellitus: Further, univariate logistic regression analysis was thoroughly performed to examine relationships between ICI-T1DM and amino acid polymorphisms at HLA-DRβ1 (237 amino acid positions) (Supplementary Table 3A), DQβ1 (237 amino acid positions) (Supplementary Table 3B, and DPβ1 (229 amino acid positions) (Supplementary Table 3C).