CYFRA21-1 ELISA kits are assays designed to detect the soluble fragment antigen of cytokeratin-19, found in the serum. Cytokeratins retain their expression as epithelial markers even after malignant transformation of cells, giving CYFRA 21–1 a role as a circulating tumor marker. It is expressed in all body tissues but elevated expression can be seen in lung cancer tissues. CYFRA 21–1 is especially useful as an indicator of non-small-cell lung cancer (NSCLC). Visit the supplier page for more information about detection range and reactivity.