Role of myc amplification and overexpression in cell growth, differentiation and death.

Genes of the myc family are apparently the most intensively studied of all nuclear oncogenes. This is because their expression is deregulated in many types of human neoplasia due to chromosomal translocation or gene amplification, and because their exact roles in the regulation of cell proliferation have remained poorly known. However, the recent characterization of several domains in Myc proteins that enable sequence-specific regulation of other growth-related genes, and the identification of proteins interacting with Myc proteins have provided insight into the function(s) of Myc proteins in both normal and neoplastic cells. While the natural target genes for Myc remain to be identified, it has become evident that myc overexpression not only promotes cell proliferation, but also increases the rate of programmed cell death.