karen macneil has more on how a form of the herpes virus could be the secret to finding a cure. >> carolyn lion's jaws one had to 80 miles to see dr. paul richards for melanoma treatment. >> i am hoping that this clinical study that i am in will help take care of its. >> after five surgeries in 52 radiation treatments, carolyn's doctors recommend that she come to bay ridge cancer care to take part in a clinical trial that uses a genetically -- a version of the herpesvirus. >> two times a month i get injected with it. >> their restricted islands -- restricted guidelines for how it is administered. a protective down has to be worn to mix it, and it must be taken to a treatment room in a container. once there, carolyn's skin is prepared for the injection that doctors hope will one day be a cure. >> it calls in the immune system, it calls in what i call the swat team. so the swat team comes in and attack the viruses, subdues the virus, but it also subdues the tumor as well. and the immune system becomes program, then, to go out into the body and attack other tumors that it might find. >> becau