PTPRN and type 1 diabetes mellitus: In type I diabetes (T1D), LIPS assays detect robust autoantibodies against a variety of known autoantigens including IA2, IA2-beta, and GAD65 [9], as well as establishing new immunoassays for such targets such as tetraspanin-7 [34,35,36,37] and PPIL2 and MLH1 [38].