Skip to main content
An official website of the United States government
Español
Government Funding Lapse
Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted.

The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov.

Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

luminal B breast cancer

(LOO-mih-nul … brest KAN-ser)
A subtype of hormone receptor-positive breast cancer. Luminal B breast cancer cells typically have estrogen receptor (ER) proteins but not progesterone receptor (PR) proteins inside them. The cancer cells may or may not have the HER2 protein on their surface. Luminal B breast cancer cells often have high levels of a protein called Ki-67, which is found only in cells that are dividing. Luminal B breast cancers tend to grow more quickly and have a slightly poorer prognosis than luminal A breast cancers.
Search NCI's Dictionary of Cancer Terms