For instance, 5 out of 18 ECS patients had Hb levels below 12 g/dl along with an ectopic ACTH-secretion due to aggressive malignant neuroendocrine neoplasm (2 small cell lung cancers, 2 high grade neuroendocrine neoplasms of the pancreas and 1 atypical pulmonary carcinoid); all of them died within three years from the initial diagnosis of CS. This evidence concerns the gene POMC and pancreatic neuroendocrine neoplasm.