To better understand the role of TLR9 in the genetic predisposition toward T1D, it is necessary to screen for more TLR9 SNPs in different regions, including introns, exons, 3’ untranslated regions and 5’ untranslated regions, and to perform haplotype analysis of TLR9 SNPs in future research. Here, TLR9 is linked to type 1 diabetes mellitus.