We are interested in signal transduction pathways between the external stimuli generated at the plasma membrane and the nuclear oncogenes or other cellular and viral genes that can regulate gene expression and cell division. Such links may be provided by oncogenes located in the cytoplasm with protein kinase activity. Thus, we have investigated the possible role raf kinase may play in transmitting a signal to the nucleus to turn on or off expression of specific genes. The two major projects are the following: A. Regulation of nuclear oncogenes expression by activated raf kinase. B. Regulation of viral gene expression by activated raf kinase.