CD4 and ductal breast carcinoma in situ: In DCIS, all subsets of TIL and PD-L1+ immune cells infiltration correlated with CXCL10 positivity while in invasive carcinoma, CD8+ and FOXP3+TIL, and PD-L1+ immune cell infiltration was significantly increased in CXCL10-positive tumors with no significant difference in CD4+ TIL infiltration.