TKT and cancer: To explore the potential application of the ERE73s-ARF (−13) constructs in cancer cell-specific gene therapy, we generated recombinant adenovirus expressing HSV-TK under the control of the ERE73 (1 + 2)-ARF (−13) and ERE73 (3 + 4)-ARF (−13) promoter constructs, generating Ad-ERE73 (1 + 2)-ARF (−13)-TK and Ad-ERE73 (3 + 4)-ARF (−13)-TK, respectively.