Anti-oncogenes and the development of tumors in the human nervous system.

Two distinct mechanisms of tumorigenesis have been identified in humans. One mechanism is associated with the activation of growth-promoting factors such as proto-oncogenes, growth factors, and growth factor receptors. However, there is overwhelming evidence for the existence of an alternative tumor mechanism that is related to the loss or inactivation of genes that normally suppress cell growth. These genes have been called "anti-oncogenes" or "tumor-suppressor" genes. They appear to be involved fundamentally in the development of many human cancers. This article reviews the potential importance of tumor-suppressor genes in tumor development and growth control in the human nervous system.