SSTR5 and digestive system neuroendocrine tumor, grade 1/2: SST5 is the second highly expressed subtype in gastroenteropancreatic neuroendocrine tumors (GEP-NETs) [7], behind the predominant expression of SST2 (at least in primary tumors) and is concomitantly expressed with SST2 in 70–100% of GEP-NETs, in breast cancer, growth hormone (GH)-secreting pituitary adenomas and in 20–50% of intestinal or bronchial NETs [5,8,9,10].