Up-regulation of p53 and ΔNp63 are interconnected but separately regulated events. Some p53 network activating signals may originate from nucleolus resulting from defective ribosome biogenesis or from cytoplasm resulting from defective translation. p53 and ΔNp63 may also integrate other signals from the cell interior as well as from the environment (eg, from growth factors). Both p53 and ΔNp63 proteins act not in isolation but as part of p53 family network.