Biphasic-type malignant mesothelioma observed in the MWCNT D low-dose group. A: H & E, low magnification of tumor tissue found on the surface of the omentum (20×). B and C: H & E, high-power view (40×). D: High-power view of anti-vimentin immunohistochemistry showing a strongly positive result (40×). E: High-power view of anti-pan-cytokeratin immunohistochemistry showing positive staining of the majority of cells (40×). F: High-power view of anti-podoplanin immunohistochemistry revealing positively stained cytoplasm of many cells (40×).