CK20

CK20 is an immunohistochemistry test that is performed to detect the cells that produce CK20. Also known as Keratin, CK20 is a cellular protein made in the colon, rectum, bladder, and urethra. It is also called cytokeratin 20 and is made by the cells on the surface of a tissue.

The CK20 test helps diagnose bladder cancer, colorectal cancer, urothelial cancer, and tumors of the lower gastrointestinal tract. This test is also ordered during or after the treatment of bladder cancer and tumors of the GI tract.

The test is performed on biopsy tissue samples. When the cells in the tissue are seen to produce this protein, they are described as CK positive or CK reactive. Doctors should be informed about any medications or allergies before conducting this test.