The 141 DCIS patients that were included in the study were all treated with BCS alone without radiotherapy or hormonal therapy. The DCIS IME was extensively interrogated on whole slides with multiplex immunofluorescent (mIF) analysis and double-staining IHC enabling the identification of lymphocytes, CD20+ B-cells, CD3+CD8+ T-cells, CD3+CD8− T-cells, CD3+FOXP3+ regulatory T-cells, CD68+ cells, CD8+Ki67+ T-cells and tertiary lymphoid structures (TLS) on the same tissue section, providing vast quantitative information on the density, composition and spatial distribution of immune cells. This evidence concerns the gene CD8A and ductal breast carcinoma in situ.