ESR1 and breast cancer: One study documented CD8 T-cells in both stroma and intratumoral regions and established an association with survival for both ER+ and ER− participants.28 Another study used QuPath, an open-source digital pathology software, to build a machine learning algorithm for scoring H&E images based on density of TILs in various tissue compartments29 and confirmed prognostic significance of TILs in TNBC, but did not consider ER+ or ER−/HER2+ breast cancer.29 None of these studies focused on spatial proximity and consistency, instead emphasizing CD8+ T-cell counts.