Angiotensin converting enzyme. A possible histologic indicator for human renal cell carcinoma

Angiotensin converting enzyme (ACE) was studied in specimens of human renal cell carcinoma by indirect immunofluorescence using rabbit antibody to human kidney ACE and fluorescein-labeled goat antibody to rabbit immunoglobulin. ACE was demonstrated in the cells of all renal cell carcinomas from 10 patients and in the cultured cells set up from 4 of them, but not in any cells of 12 extrarenal carcinomas of prostate, lung, and alimentary tract. These results suggest that immunohistologic detection of ACE is of value in the histologic diagnosis of renal cell carcinoma.