A 48 to 72 hour fasting test is usually carried out, and once the patient experiences hypoglycemic symptoms, those biochemical tests are carried out, in which hypoglycemia, hyperinsulinemia, and elevated levels of c-peptide suggest insulinoma, while low levels of c-peptide and a positive circulating sulfonylurea indicate exogenous insulin administration.[2,7]. The gene discussed is INS; the disease is Hyperinsulinemia.