A very high mHVI, particularly above the optimal cutoff value of >83 μIU/mL, which has 83% sensitivity and 93% specificity, may suggest insulinoma over nesidioblastosis, as it reflects a marked insulin hypersecretion that is more characteristic of insulin-producing tumors than the more gradual insulin overproduction seen in nesidioblastosis [11]. This evidence concerns the gene INS and pancreatic insulinoma.