The mutator gene refers to a gene that causes mutations or changes in the genetic material of an organism. The term "mutator gene" is often used interchangeably with "mutagenic gene" or "mutagenesis gene," as these genes have similar roles in promoting genetic variation. Other synonyms for mutator gene include "mutation-prone gene," "genetic instability gene," and "hypermutable gene." These terms all refer to genes that increase the rate of mutation and contribute to diversity among populations of organisms. Understanding mutator genes and their effects is important in fields such as genetics, evolutionary biology, and cancer research.