Therefore, this study shows for the first time, to the best of our knowledge that resveratrol and pterostilbene can exhibit antitumor activities and reduce tumor load by two distinct mechanisms; resveratrol through cell cycle arrest (down regulation of PCNA) and pterostilbene through apoptosis (upregulation of caspase-3; Figure 5). The gene discussed is PCNA; the disease is neoplasm.