After brain cancer, the most common solid tumor in children is neuroblastoma. Some versions of neuroblastoma are highly deadly, with fewer than half of patients cured despite surgery, radiation, high dose chemotherapy, bone marrow transplantation, and treatment with vitamin A forms that cause cells to mature and stop dividing. It is widely believed by most pediatric hematologists/oncologists that we have reached a plateau in our use of these treatments, and further refinements will only bring minimal improvements in increasing patient survival.