Functional activation of p53 by inhibition of negative regulators in leukemic cells is a useful approach to enhance the cytotoxicity of existing chemotherapeutic agents.13, 16 In addition, restoring wild type functions to mutant p53 by using small molecule inhibitors has proven to be an effective strategy to induce apoptosis in cancer cells.37, 38 Our results obtained in the NB-4 cell line indicate that FK866-mediated acetylation of mutant p53 restores its ability to execute tumor suppressive functions. This evidence concerns the gene TP53 and cancer.