HLA-DQB1 and type 1 diabetes mellitus: HLA-DQB1 position 57, HLA-DRB1 position 13 or HLA-DRB1 position 71 amino acid variants, which have been reported to independently drive type 1 diabetes risk and explain >90% of the type 1 diabetes–HLA association [41], were not associated with stimulated C-peptide at DCCT eligibility.