Vaccines contain substances that help us make antibodies. Different antibodies help protect us against a variety of harmful things. GD2 and GD3 gangliosides are substances found on the surface of most melanoma cells. They are also occasionally found on some normal cells. Large quantities of antibodies called monoclonal antibodies have been prepared in the laboratory against GD2 and GD3 and given to patients with metastatic melanoma. In about 10% of cases this has resulted in clinically relevant regression of melanomas. These monoclonal antibodies are not currently available or used in the clinic but studies in the laboratory indicate that vaccines against GD2 and GD3 can be as effective as monoclonal antibodies.