CDKN2A and central nervous system cancer: Through intracerebral injection of cells producing RCAS/PDGF-B virus, gliomas were induced in a cell specific manner in newborn Ntv-a and Gtv-a mice with either wild type, p16Ink4a−/−, p19Arf−/− or p16Ink4a−/−/p19Arf−/− background.