INS and type 1 diabetes mellitus: The autoantibodies that help to define pre-T1D and T1D include: insulin autoantibody (IAA),12 glutamic acid decarboxylase antibody (GADA),13 insulinoma-associated protein 2 autoantibody (IA-2A),14 and zinc transporter 8 antibody (ZnT8A).15 Testing for at least two of these autoantibodies at diagnosis is now considered standard of care in T1D.