PECAM1 and neoplasm: Breast G1/G2, G3 grade tumor and control specimens were immunostained for CD68, CD163, tryptase and CD31 to estimate total macrophages, M2-macrophages (Figure 5A–5H and Figure 6A–6H), mast cells (Figure 6A–6H), endothelial cells (Figure 7A–7H) in the interstitial spaces and in periglandular position.