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Ki-67 proliferation index

(… proh-LIH-feh-RAY-shun …)
A way to measure how fast cancer cells in a tumor are dividing. Ki-67 is a protein that is found only in cells that are dividing. A high Ki-67 proliferation index means many cells are dividing quickly and that the cancer is likely to grow and spread. A Ki-67 proliferation index over 30% is typically considered high. The Ki-67 proliferation index may be used to help predict how well some cancers, such as breast cancer, will respond to certain treatments, such as chemotherapy. Also called Ki-67 score.
Search NCI's Dictionary of Cancer Terms