The correction by ancestry indicated that the DRB1*16 allele and -DRB107-DQB1*0201 haplotype were protective against T1D; that the allele DQB1 *0501, which was initially found to be protective, was actually neutral; and that the DRB1*10-DQB1*0501 haplotype was protective. Here, HLA-DRB1 is linked to type 1 diabetes mellitus.