CD8A and ductal breast carcinoma in situ: Median DCIS intraepithelial density of lymphocytes, CD3+ T-cells, CD3+CD8− T-cells, CD3+CD8+ T-cells, CD3+FOXP3+ T-cells and CD20+ B-cells was significantly lower than stromal immune cell density (P < 0.001, Supplementary Fig. 1 and Supplementary Table 5).