SLC30A8 and Autoimmunity: In particular, the amino acid residue 325 (R325W) defined by the SLC30A8 polymorphism is critical for humoral autoimmunity to this autoantigen, and binding of ZnT8A against two isotypes (ZnT8-325R, ZnT8-325W) depends on the patient’s SLC30A8 genotype [55,56].