DHTKD1 and gastric cancer: We have developed an attenuated adenovirus (Ad), OBP-301 (Telomelysin), which drives the E1A and E1B genes for viral replication under control of the human reverse transcriptase promoter, and we previously confirmed its antitumor effects in various human tumor cells including gastric cancer.16, 17, 18, 19 Furthermore, a phase I trial of OBP-301 for patients with various advanced solid tumors demonstrated that OBP-301 is well tolerated by patients.20