These results indicate that co-infection of Adv-p53, Adv-APAF1 and Adv-Casp9 induced remarkably enhanced apoptotic cell death in comparison with that induced by single or double infection of Adv-p53, Adv-APAF1 or Adv-Casp9 in the two glioma cell lines. Here, CASP9 is linked to infection.