CASP3 and neoplasm: Both lines of evidence from IHC and Western blotting do suggest that PDOX exerts its anti-tumor effects at least via two mechanisms of action: direct inhibition of tumor proliferation which could produce short-term and immediate antitumor effects, and activation of P53/caspase 3-mediated apoptosis which could produce long-term and durable antitumor effects (Supplementary Figure 1B).