Most cases of T1DM are preceded by the appearance of islet autoimmunity (IA) that can be serologically confirmed by the presence of at least one autoantibody specific for the pancreatic islets, including insulin (IAA), glutamic acid decarboxylase (GADA), protein tyrosine phosphatase-like insulinoma antigen 2 (IA-2A), and zinc transporter 8 (ZnT8A). Here, INS is linked to type 1 diabetes mellitus.