Edit page | Page history | Printable version

Cancer-critical genes are grouped into two broad classes, according to whether the cance risk arises from too much activity of the gene product, or too little. Genes of the first class, for which a gain-of-function mutation drives a cell toward cancer, are called proto-oncogenes; their mutant overactive forms are called oncogenes. Genes of the second class, for which a loss-of-function mutation creates the danger, are called tumour suppressor genes.