Cytokeratin 7 and 20 in Tumor Identification and Classification

The document discussed the role of cytokeratins, particularly CK7 and CK20, in epithelial cells and their importance in tumor identification and classification. Cytokeratins, as intermediate filament proteins, were crucial for epithelial cell development and differentiation, with specific expression patterns that remained consistent even in malignant transformations. These patterns were used to distinguish between primary and metastatic carcinomas, aiding in accurate cancer diagnosis. The document highlighted the division of cytokeratins into type I and type II based on molecular weight and isoelectric points, and emphasized the significance of antibodies against cytokeratins in identifying carcinoma origins.