Gene Therapy: Treatment that alters a gene. In studies of gene therapy for cancer, researchers are trying to improve the body's natural ability to fight the disease or to make the cancer cells.
Graft-Versus-Host Disease: A reaction of donated bone marrow against a patient's own tissue. Also called GVHD.
Mutation: Any change in the DNA of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial.
