GHRL and pancreatic insulinoma: Fasting serum ghrelin levels were significantly lower in 23 patients with insulinoma than in controls (median 4.2, range 1.4-17.9 pg/mL vs. 14.8, range 4.8-44.3 pg/mL; P < 0.01; Supplementary Figure 3A), consistent with our previous findings (10).