HLA-DRB1 and type 1 diabetes mellitus: Because the frequency of the HLA-DRB1, -DQB1, and INS-VNTR alleles, as well of the PTPN22 variants, was similar between genders (data not shown), the higher frequency of T1D women in our cohort may be due to other polymorphisms, such as the T allele in the CD226 rs763361 variant that was suggested by Mattana et al. 5 in the Brazilian cohort, or to environmental factors.