INS and benign neoplasm: Another study confirmed these results and also determined that median insulin (21.0 vs 12.3 μIU/mL), median proinsulin (190 vs 83.5 pmol/L), and median C‐peptide (4.1 vs 3 ng/mL) concentrations were higher in people with malignant insulinomas than in those with benign tumors.