The LC/MS data obtained from the two glucagonoma cases (Case 1 pre‐ and post‐treatment, and Case 2), an insulinoma (Case 3) and 62 control samples from healthy individuals were interrogated for glucagon, CHGA, CHGB, SCG2, insulin, c‐peptide, and the internal standard bovine insulin. The gene discussed is INS; the disease is pancreatic insulinoma.