For instance, TCF7L2 variants—the strongest genetic risk factor for type 2 diabetes [2]—were associated with a higher C-peptide AUC, a lower glucose AUC during an OGTT and single autoantibody positivity near diagnosis, particularly in individuals older than 12 years of age, in the type 1 diabetes TrialNet study [3], and a lower frequency of type 1 diabetes-associated HLA genotypes in the T1D Exchange study [4]. The gene discussed is TCF7L2; the disease is type 1 diabetes mellitus.