KRT5 and neoplasm: To further delineate the underlying mechanisms, we examined tumor morphology by H&E staining and performed immunofluorescence staining (IF) to analyze the expression of cytokeratin 5 (CK5), a marker for SCCs, and vimentin (Vim), a mesenchymal marker, both of which are important for the epithelial–mesenchymal transition (EMT) process.