The maximal C-peptide reached during the test (after the arginine during hyperglycemia and GLP-1 infusion) was 22.3-fold [95% CI: 5.6–89.1, P = 0.003] higher than baseline C-peptide concentration or the limit of detection (when baseline C-peptide was undetectable). The gene discussed is GCG; the disease is Hyperglycemia.