Cancer antigen 72-4 (CA72-4) is a tumor-associated-glycoprotein (TAG-72) used as a tumor marker for gastrointestinal and ovarian cancers. Elevated CA72-4 levels in serum and plasma are seen in the pancreas, gallbladder, colon, cervix, and endometrium carcinomas. There is a correlation between serum CA72-4 levels and tumor stage/size compared to other commonly used biomarkers. CA72-4 is also an independent marker for the therapeutic monitoring and care of ovarian cancer patients who are CA125 negative.