Anti-ERCC1 immunocytochemistry on cell block core of malignant pleural mesothelioma, using Mab 8F1 and D-10 with CC1-mono and H2-60 protocols. Arrow: Surrounding non-tumoral cells, including lymphocytes, macrophages and neutrophil granulocytes. Arrowhead: Unspecific plasma membrane staining with D-10. 200 × original magnification. Inset lower left: Staining of intracellular mucin vacuoles of a mucinous adenocarcinoma of unknown origin. 400 × original magnification.