Fig. 3.

Representative images of different immune reaction and PD-L1 expressions in two invasive metaplastic breast carcinomas, as detected with anti-PD-L1 multiplex immunohistochemistry (anti-CD8 in green, anti-CD163 in red, and anti-PD-L1 in brown). a, b One invasive metaplastic carcinoma with no PD-L1 expression, only scattered CD163⁺ cells and very rare CD8⁺ cytotoxic T-cells in the peritumoral stroma. c, d One invasive metaplastic carcinoma with strong PD-L1 expression in tumor cells and stromal cells, diffuse CD163⁺ cells and CD8⁺ cytotoxic T-cells in tumoral stroma and peritumoral stroma. Magnification: × 100