Improved clinical response to chemotherapy was observed in KRAS-mutant patients suffering from mCRC and pancreatic neuroendocrine neoplasm grade-3 (PanNEN-G3) [54–56], while in other clinical trials, KRAS mutational status did not have prognostic value for stage II/III colon cancer receiving either FU/FA alone or in combination with irinotecan [52]. This evidence concerns the gene KRAS and pancreatic neuroendocrine neoplasm.