Skip to main content
An official website of the United States government
Español

9p21

A specific part of chromosome 9 called p21, which has a gene that may be involved in stopping tumor cell growth. In some types of cancer cells, including bladder cancer cells, this small part of chromosome 9 may be missing. This may cause cancer cell growth. Checking for 9p21 may help diagnose cancer or find out if cancer has come back. 9p21 is a type of tumor marker.
Search NCI's Dictionary of Cancer Terms