Chromogranin A
Chromogranin A (ChgA) is a 439-amino acid protein. It is a member of the granin family of neuroendocrine secretory proteins, and it is found in secretory vesicles of neurons and endocrine cells. Its levels are increased in tumours of neuroendocrine origin, including carcinoids, pheochromocytomas, neuroblastomas, medullary thyroid carcinomas, islet cell tumors, or some tumours of pituitary gland.