In terms of monitoring parameters, autoantibodies, such as insulin, insulinoma-associated protein 2 (IA-2), glutamic acid decarboxylase (GAD) or zinc transporter isoform 8 (ZT8), act as biomarkers to detect the preliminary onset of diabetes, as individuals who tested positive for more than 50% of these autoantibodies compared to single β-cell antigens are at a greater risk of developing T1DM [19,20]. This evidence concerns the gene GAD1 and diabetes mellitus.