To identify cultured human tumor lines on the basis of polymorphic and tissue specific enzyme patterns. We will analyze cultured human cell lines, malignant and corresponding normal patient tissues, and tumors of human malignant cells produced in the athymic nude mouse. Methods will include electrophoresis using starch gels and Cellogel, isoelectric focusing in polyacrylamide gels, and spectrophotometric assays. The analysis will be based upon cell lines and tumor lines already available in the laboratory. The objective is to provide evidence that these lines are bona fide representatives of the tumors and the types of tumors that they are claimed to be.