CGA and neuroendocrine neoplasm: Furthermore, according to recent North American Neuroendocrine Tumor Society (NANETS) and European Neuroendocrine Tumor Society (ENETS) consensus guidelines [28,29] as well as ESMO guidelines for NETs diagnosis [5], CgA was considered as a general biomarker for NETs, and CgA can be used as a marker in patients with both Functional PNET and NF-PNET [28,29].