TP53 and cancer: It was suggested that NPs (e.g. ZnO NPs) could selectively induce apoptosis of cancer or viral-infected cells (in this review) via a ROS-mediated mitochondrial intrinsic apoptotic pathway and enhancing p53-dependent programmed cell death or via the autophagy-signaling pathway (Jiang et al. 2018); this would be a revolutionary application of metal-based NPs.