CD80 and breast carcinoma: Tissue section staining with CD68 (macrophage lineage marker), CD80 (M1-like) and CD163 (M2-like) led to the observation that while in normal samples the macrophage population comprises a combination of comparable numbers of cells expressing CD80 and CD163, in breast carcinoma samples this population is predominantly composed of CD163-positive cells, and thus associated with an M2 (alternative) macrophage polarization phenotype (Fig. 4).