After completing Metro-Mali 01 we aimed at developing a protocol that would be more efficient without increasing cost nor toxicity. We designed Metro-Mali 02 as a combination of metromomic chemotherapy and drug repositioning. Thus we added valproic acid as an HDAC inhibitor, an established new anticancer strategy. Valproic acid has already been demonstrated to have some efficacy as an anticancer agent when given alone by the Children Oncology Group (http://www.ncbi.nlm.nih.gov/pubmed/...). (...)