Schematic representation of adenoviral vector AdSox9 construction. An HA-tagged cDNA coding sequence of human Sox9 was subcloned into a shuttle vector, pAdTracK-CMV. Resultant pAdTrack-Sox9 was next used to generate adenoviral recombinants through homologous recombination with the ad-enoviral backbone vector, pAdEasy-1, in BJ5183 bacterial cells. After being linearized with Pac I, the adenoviral recombi-nants were used to produce ad-enoviruses in HEK 293 packaging cells, resulting in an AdSox9 ad-enoviral vector that contained a built-in GFP expression cassette. A recombinant adenoviral vector expressing GFP alone also was constructed as a control vector (AdGFP). For detailed information about AdEasy System, please refer to He et al., Proc Natl Acad Sci (AM) 1998;95:2509, and www.coloncancer.org/adeasy.htm