Post-chemotherapy immune cell subpopulation profile and breast cancer prognosis. A) unsupervised hierarchical clustering analysis of post-chemotherapy immune cell populations generated two groups (named as Y and Z); each column represents a patient and each row represents an immunohistochemical marker. B) distribution of immune cell populations in post-chemotherapy cluster groups Y and Z; statistically significant higher infiltration was shown in cluster Y for all populations (CD3, CD4, CD8, CD20, Foxp3, CD68), Mann–Whitney U-test. C) Kaplan-Meier curves showed a worse disease-free survival for patients with tumors belonging to post-chemotherapy immune cluster Y (P = 0.01). D) disease free survival curves according to post-treatment CD68 infiltration in residual tumor (P = 0.055). E) Kaplan-Meier disease free survival curves according to level of post-treatment CD3 infiltration in residual tumor, showing an increasingly worse prognosis as CD3 infiltration increases (P = 0.038). Hazard ratios (HR) and 95%CI calculated according to Cox proportional hazard regression models.