GAD1 and type 1 diabetes mellitus: Notably, several CD4 and CD8 islet antigen–specific TCRβ chains were similar in sample frequency and template number between the cohorts or even higher in controls relative to cases or new onsets (e.g., GAD-specific CD4 TCRβs in Fig. 4B); these TCRβ sequences were not deemed to be associated with preclinical or clinical T1D onset.