HLA-DRB1 and type 1 diabetes mellitus: Three HLA DRB1-DQB1 haplotypes, i.e., DRB1*04:05-DQB1*04:01, DRB1*08:02-DQB1*03:02, and DRB1*09:01-DQB1*03:03, confer susceptibility to Japanese T1D.