In this study, we have shown that the high infiltration of CD4+, CD8+, and FOXP3+ T cells and the presence of PD-L1+ immune cells were generally associated with aggressive features of DCIS including high nuclear grade, comedo-type necrosis, HR negativity, and high Ki-67 proliferation index. This evidence concerns the gene FOXP3 and ductal breast carcinoma in situ.