CGA and neuroendocrine neoplasm: Chromogranin A (CgA), mostly known as a nonspecific neuroendocrine tumor marker, was the first glycoprotein from the granin family characterized as a prohormone for various bioactive peptides including vasostatin I/II (VS-I, VS-II), catestatin (CST), chromofungin (CHR), pancreastatin (PST), WE-14, and others.