To examine the role of epithelial Cav1 in prostate tumor radiosensitivity in vivo, we next compared the response to a single high dose irradiation in PC3(−) tumor xenografts to that of Cav1-expressing PC3(+) cells, because the above in vitro data suggested that the Cav1-silenced PC3 cells are more sensitive to IR (Fig. 2). The gene discussed is CAV1; the disease is neoplasm.