Not all viruses are bad. In a recent study, researchers showed that viruses could be directed to attack brain tumors, while also triggering the patient’s immune system to do the same. Previous experiments have demonstrated this mechanism, but this was the first time a virus was successfully directed at brain tumors. The hope now is that the additional effect of the virus on enhancing the body’s immune response will increase the amount of tumor cells that are killed by treatments such as radiotherapy and chemotherapy.