CASP3 and neoplasm: The percentage of tumor cells with activated caspase-3 in the apoptin-modified MSCs group was markedly higher than that in the MSCs group (16.5±2.9% at 24 h and 27.3±2.0% at 48 h vs. 3.4±1.1% at 24 h and 2.2±0.6% at 48 h).