The University of Missouri Mutant Mouse Regional Resource Center is one of four regional centers comprising the MMRRC (http://www.mmrrc.org/). The overall goal of the MMRRC is to provide a center for accepting and distributing high quality, well characterized mutant mice. To this end, the MMRRC will select and import mouse strains important to the biomedical research community; rederive mice to a pathogen-free status; cryopreserve gametes and/or embryos; perform genotyping and infectious disease monitoring to assure the highest quality of mice available, and distribute live mice, cryopreserved germplasm or tissues to investigators.