TP53 and neoplasm: Loss of the TP53 tumor suppressing function eliminates the damage-sensor from the apoptosis circuitry, and these ends can also be achieved by increasing the expression of anti-apoptotic regulators (Bcl-2) and survival signals (Igf 1/2), by downregulation of pro-apoptotic factors such as Bax, Bim and Puma, or by short-circuiting the extrinsic ligand-induced death pathway.