There are several different types of white cells in the blood. We are interested in immune cells in the blood called T-cells. These T-cells detect foreign substances in the body (like viruses and cancer cells). We are trying to learn more about how the body fights these foreign substances. Our goal is to develop cancer vaccines which would teach T-cells to detect and kill cancer cells better. We know that in healthy people the immune system effectively protects against recurrent virus infection. For example, that is why people only get "mono" (mononucleosis) once under normal circumstances. When the body is infected with the "mono" virus, the immune system remembers and prevents further infection. We are trying to use the immune system to prevent cancer relapse. To test this, we will give two vaccines which have been used to measure these immune responses. Blood samples will be studied from cancer patients and will be compared to similar samples from normal subjects.