TP53 and neoplasm: CR highly stimulates SIRT1 in mice with p53 deficiency, suggesting that deacetylation of mutant p53 results in a reduced level.333 αKG has the capacity to repress tumour growth depending on p53 status, while succinate has been found to competitively inhibit the effect of αKG to abrogate p53-mediated tumour suppression.