With respect to potential mechanisms of action, gene-expression profiling comparing pre- and post-Ad-p53 tumor biopsies showed strong upregulation of genetic pathways involved in antitumor immune responses, including IFN-gamma activation, an increased CD8 + T-cell signature, with concomitant downregulation of TGF-beta and IL10 gene profiles. This evidence concerns the gene CD8A and neoplasm.