GAD1 and type 1 diabetes mellitus: Ninety percent of T1D patients develop autoantibodies against pancreatic β‐cell‐associated antigens, such as insulin autoantibodies (IAA), GAD autoantibodies (GADA), insulinoma‐associated antigen‐2 autoantibodies (IA‐2A), and zinc transporter 8 autoantibodies (ZnT8A) [1].