We have investigated the mechanisms of oncogene regulation in human malignancies. A large body of evidence has implicated the c-myc oncogene in normal cell growth and differentiation as well as in the development of a wide range of human cancers. This project is designed to study both the mechanisms of transcriptional regulation of the c-myc gene and to examine functional properties of the c-myc protein product. The major sub- projects are the following: A) Transcriptional regulation of the c-myc oncogene in normal and neoplastic cells. B) Effect of differentiating agents on the function of transcription factors and their role in the regulation of the c-myc gene. C) The role of the c-myc protein in normal and neoplastic growth.