Fig. 1

Distribution of tumor-infiltrating lymphocytes (TILs) and immune cell subpopulations in triple-negative breast cancer (TNBC). Immunophenotypic characterization of lymphocyte components showed that the presence of elevated TILs positively correlated with the density of CD4+, CD8+, and forkhead box protein 3 (FOXP3+) lymphocytes in TNBC in the discovery (a) and the validation (b) cohorts. Pearson’s correlation coefficients (r) for each cell subpopulation are shown. Cell density was scored by determining the average number of stained cells in three distinct high power fields (HPF). c-f Representative images of hematoxylin and eosin sections from TNBC samples with high (c) and low (d) TIL scores. Representative immunohistochemical staining of CD4, CD8, and FOXP3 in serial sections of TNBC specimens with high (e) and low (f) lymphocytic infiltration. Scale bars represent 50 μm