However, p53 mutations, mdm2 amplification/overexpression, or deletions of the CDKN2A/p14ARF tumour-suppressor gene often render the gliomas resistant to these therapeutic approaches (Frankel et al, 1992; Van Meir et al, 1994; Iwadate et al, 1996). This evidence concerns the gene TP53 and central nervous system cancer.