HLA-DRB1 and type 1 diabetes mellitus: The frequencies of T1D susceptible haplotypes DR3 and DR9 in ICI-DM patients were lower than those in T1D patients (2.3% vs 17.7%; P=0.011 and 15.9% vs 34.4%; P=0.025), whereas the frequencies of T1D protective haplotypes DRB1*1101-DQA1*05-DQB1*0301 and DRB1*1202-DQA1*0601-DQB1*0301 were significantly higher in ICI-DM patients (13.6% vs 2.1%; P=0.006 and 15.9% vs 4.2%; P=0.017).