CA-125 (cancer antigen 125, or carbohydrate antigen 125) also known as mucin 16 or MUC16 is encoded by the MUC16 gene in humans. MUC16 is a member of the mucin family of glycoproteins. CA-125 is most consistently elevated in epithelial ovarian cancer, but can be expressed in a number of gynecologic (endometrial, fallopian tube) and non-gynecologic (pancreatic, breast, colon, and lung) cancers. It may also be elevated in cases of benign abnormalities such as endometriosis.