Finally, in order to identify possible mechanisms that could explain the ability of APE to reduce the expression of the efflux pumps, we have analyzed the effect of APE on the expression of N-MYC, the main transcriptional factor involved in the onset and progression of neuroblastoma [12] and able to act as a transcriptional factor in the regulation of ABC pumps, especially for ABC-C1. Here, MYCN is linked to neuroblastoma.