PROJECT SUMMARY - OVERALL The Mutant Mouse Resource and Research Center (MMRRC) is the nation’s largest public mutant mouse archive and distribution repository organization. The primary goal is to facilitate research by identifying, acquiring, evaluating, characterizing, cryopreserving, and distributing mutant mouse strains to qualified biomedical investigators. The MMRRC was established by the NIH to ensure the preservation, dissemination, and development of valuable mutant mouse lines and data generated by research scientists. The MMRRC is a consortium of four Centers, each hosting an archive and distribution repository, and an Informatics Coordination and Service Center (ICSC) within a trans-national network regionally distributed across the United States. The Centers collectively serve the needs of the nation’s biomedical research community, ensuring access to and optimizing utilization of unique transgenic, knockout, and other genetically modified mutant mice and related biomaterials, services, and new technologies. The Centers collectively import, verify, maintain, and distribute mice, gene-targeted embryonic stem (ES) cells, and germplasm of genetically unique, scientifically valuable mice. Centers also provide services and procedures to assist investigators using genetically altered mice for research. Finally, Centers conduct resource-related research, often collaboratively, to further refine and develop mutant mouse lines to improve the reproducibility and translatability of mouse models for biomedical research. By depositing their mutant mice in repositories at the Centers, NIH-funded investigators fulfill their obligation under the NIH Sharing Policy. In return, each of the Centers strives to preserve the unique genetics, protect the germplasm, assess the genetic quality, and provide these models for the benefit of research scientists and investigators across the nation and the globe. In doing so, the MMRRC preserves the investment NIH made in these model