Chromogranin A

Chromogranin A (CgA) is a major acidic glycoprotein that is co-stored and co-secreted with catecholamines and other peptide hormones in the secretory granules of neuroendocrine cells. Chromogranin A acts as a precursor to several smaller, biologically active peptides (such as vasostatin, pancreastatin, and catestatin) after undergoing enzymatic cleavage. Within the cell, it plays a crucial role in the generation of secretory granules and the regulation of hormone secretion. Because it is widely distributed throughout the neuroendocrine system, it serves as an excellent universal marker for neuroendocrine differentiation.