Anti-Cytokeratin (OSCAR) is well suited to distinguish epithelial carcinoma from non-epithelial malignancies and is used to aid epithelial tumor classification. This antibody has been used to characterize the source of various neoplasms and to study the distribution of keratin containing cells in epithelia during normal development and during the development of epithelial neoplasms. This antibody stains cytokeratins present in normal and abnormal human tissues and has shown high sensitivity in recognizing epithelial cells, and carcinomas.