A common non-synonymous single-nucleotide polymorphism (SNP) of SLC30A8 rs13266634 (C/T polymorphism) encodes either arginine (R) by the C allele or tryptophan (W) by the T allele at aa325 of ZnT8 (14) suggesting that rs13266634 SNP might be critical for humoral autoimmunity in T1D (11,15). Here, SLC30A8 is linked to type 1 diabetes mellitus.