COPS5 and xerostomia: For example, curcumin can sensitize nasopharyngeal carcinoma cells to radiation through the regulation of ROS generation, Jab1/CSN5, and noncoding RNA expression.160 Resveratrol and berberine have also been shown to enhance radiosensitivity in nasopharyngeal carcinoma cells.161, 162 Furthermore, radiotherapy has the problem that it inevitably involves the exposure of noncancerous tissues to radiation, leading to side effects such as xerostomia, hepatotoxicity, or pneumonitis.