The presence of tumor-infiltrating lymphocytes (TILs) varied significantly in the tumors of African-American and European-American women with triple negative breast cancer (TNBC)

TNBC is a highly aggressive breast cancer subtype that afflicts African-American women at a higher rate than white women, and often involves a worse prognosis. Previous research has shown that African-American women tend to develop more aggressive subtypes of TNBC than European-American women, exacerbating the disparity in survival.