This antibody labels the cytokeratin 7 (CK7) protein in the cytoplasm of most ductal, glandular, and transitional in both normal and neoplastic cells. It is a useful tool for classifying adenocarcinomas of lung, breast, endometrium, thyroid gland, ovary, and chromophobe renal cell carcinomas when CK7 is positive and when it is used in a panel of antibodies. It is a useful tool for classifying colonic and prostate lineage tumors when CK7 is negative and when it is in with a panel of antibodies.