ESR1 and breast cancer: In that study, a 21–28% reduction (stromal vs intratumoral TILs, respectively) in the hazard of BC-specific mortality was shown in all ER negative tumors (HER-2 positive and TN); for HER-2- and ER-positive tumors, a 27% reduction in the hazard of BC-specific mortality was shown with intratumoral CD8+ TILs (37).