Type 1 diabetes is characterized by the presence of antibodies to a 65 kD Glutamic Acid Decarboxylase antigen (GAD), Insulinoma-associated protein-2 antibodies (IA-2 orICA512), which is now known as protein- tyrosine phosphatase (PTP),[7] insulin autoantibodies (IAAs), and islet cell autoantibodies (ICAs), in blood that identify the autoimmune process that leads to β cell destruction.[2]. The gene discussed is GAD1; the disease is type 1 diabetes mellitus.