Pre-treatment lymphocyte subpopulations profile of breast cancer and pathological response to neoadjuvant chemotherapy. A) representative digital images (100x) of ductal invasive carcinoma of the breast showing CD3, CD4, CD8, CD20, CD68 and Foxp3 staining (scale bar, 100 μm). B) unsupervised hierarchical clustering analysis of pre-chemotherapy TIL subpopulations yielded three groups or immune clusters (arbitrarily named A, B and C); each column represents a patient and each row represents an immunohistochemical marker. C) pathologic complete response distribution according to pre-chemotherapy immune cluster group. D) differential distribution of lymphocyte populations (CD3, CD4, CD8, CD20, Foxp3, CD68) according to pathological response to neoadjuvant chemotherapy; differences were statistically significant for CD3, CD4 and CD20 and non significant for CD8, Foxp3 and CD68. Statistical analysis: Mann–Whitney U-test. *, P ≤0.05. TIL, tumor infiltrating lymphocytes.