PPP1R13L and cancer: The oncoprotein inhibitory member of theASPP family (iASPP) functions as an upstream modulator of p53; iASPPreduces the expression of p53 and renders cancer cells resistant toapoptosis.353,354 Knock-down of iASPP by siRNAstimulates the expression of p53 and make cancer cells susceptibleto etoposide-mediated apoptosis.355 Althoughthe combination of etoposide and siRNA is beneficial in cancer elimination,356 further progress has to be made to enhancethe efficacy of these agents.