To quantify differences in CaSR expression, H scores for each sample were generated using QPath software, and when compared to normal islets, and normal adjacent islets, a significant reduction in CaSR expression was observed in gastrinomas (5.75‐fold, and 6.3‐fold, both p < .0001), insulinomas (2.3‐fold p < .005, and 2.5‐fold p < .005), and NF‐PNETs (1.9‐fold p < .05 and 2‐fold p < .005) (Figure 2A, B), consistent with the RNA results. This evidence concerns the gene CASR and pancreatic insulinoma.