CD8A and breast cancer: Although African American women with breast cancer are noted to have higher levels of CD8+ T cells, as noted in a study of 688 invasive breast cancer tumor samples (550 Black and 138 White), it has been shown that the high CD8+ proportion does not translate to a better prognosis in AA women, because the CD8+ population is made up of a higher percentage of exhausted CD8+ T cells, which is linked to lower survival [35,36].