Although these drugs certainly deserve more investigations with respect to the enhancement of DOX-induced antitumoral responses (e.g. pretreatment of the cells with the drugs; application of the drugs at a higher dose; combination with lower or higher DOX concentrations), we focused on PI103, which simultaneously enhanced DOX-induced proliferation inhibition, induction of apoptosis, and activation of caspase 3 in all three sarcoma- and RMS-derived cell lines investigated. This evidence concerns the gene CASP3 and sarcoma.