A protective gene that normally limits the growth of tumors. When a tumor supressor is mutated, it may fail to keep a cancer from growing. BRCA1 and p53 are well-known tumor suppressor genes.

Dr. Lawrence Brody, of the National Human Genome Research Institute's Genetic and Molecular Biology Branch, defines tumor suppressor gene.

Related terms: BRCA1/BRCA2, cancer, gene, oncogene, p53.