PPY and lung carcinoid tumor: Lung carcinoid tumors can be responsible for secreting many hormones and hormone-like peptides causing a wide range of symptoms and conditions such as 5-hydroxy indoleacetic acid (5-HIAA) causing carcinoid tumors which are twice as common compared with neuroendocrine-induced EAS, other hormones include growth hormone-releasing hormone (GHRH), anti-diuretic hormone (ADH), gastrin, pancreatic polypeptide, human chorionic gonadotropin (HCG) and chromogranin-A [12].