MKI67 and breast cancer: Prompted by a recent study showing a direct correlation between CD8 + and CD163 + in breast cancer patients [23], we observed that increased CD8 + , CD8 + Ki67 +, and CD8 + TCF1 + density was associated with high PD-L1 score, CD163 +, and infiltration by CD163 + PD-L1 + cells, irrespective of the breast cancer subtype (Fig. 6a, b, c and Supplementary Fig. 8a, b).