The p53 tumor suppressor pathway is active in cells that are subjected to stress and/or
damaged, where it promotes cell cycle arrest or apoptosis. In contrast, in normal cells that
are not exposed to stress signals and in tumor cells p53 is tightly kept in check or completely
silenced. In most, if not all, tumor cells p53 is indeed inactivated by mutations in the p53
locus or by alternative, yet unclear, mechanisms that impinge directly or indirectly on p53
function. Recent biochemical and genetic data indicate that tumor cells hijack and enforce …