In the present study, we investigated the effects of Ad-VT (Ad-hTERTp-E1a-Apoptin), a new recombinant OV that can specifically replicate in tumor cells and express apoptin protein efficiently (thus playing an effective role in tumor cell death) [25], on gemcitabine-resistant and paclitaxel-resistant lung cancer cells in vitro and on their corresponding xenograft tumor models in vivo. The gene discussed is DHTKD1; the disease is lung cancer.