The goals of this project are: (1) to identify transforming genes in human tumor cells by DNA-mediated gene transfer techniques; (2) to isolate these human oncogenes by molecular cloning techniques; (3) to isolate the normal homologues of these human oncogenes; (4) to biochemically compare the transforming genes and their respective normal homologues to establish the molecular changes that lead to oncogenesis; (5) to characterize the transcriptional and translational products of these human oncogenes to understand the mechanisms by which they induce malignant transformation.