PECAM1 and neoplasm: IHC carried out on FFPE tissue sections allowed us to identify, quantify, and assess spatial distribution of tumor-infiltrating CD3+ T, CD4+ T helper and CD8+ T cytotoxic lymphocytes, FOXP3+ Treg lymphocytes, CD68+ macrophages, CD163+ alternatively activated M2-like macrophages, and CD31 positive microvessels.