Project Summary/Abstract (Core A: Administrative Core) The Administrative Core will facilitate coordination among all other cores and supported grants. The purpose of this center is to provide services that were part of our P50 center from 2014 to 2024. That center led to the development of numerous interacting projects and grants that we will continue to support. Dr. Palmer will serve as the Center Director; consistent with PAR-23-049 he will also serve as the PI of the Administrative Core. He will be assisted by Dr. Oksana Polesskaya, who has served as the Scientific Coordinator for the P50 since January 2015; she will continue to serve in a similar role in the proposed P30 center. We have identified seven Specific Aims for the Administrative Core: Specific Aim 1. Promote interactions among users of heterogeneous stock (HS) rats. Specific Aim 2. Maintain the center’s website (www(dot)ratgenes(dot)org). Specific Aim 3. Maintain the Center’s Database and Support the Center’s Data Management Plan, Specific Aim 4. Maintain an External Advisory Board (EAB), Specific Aim 5. Promote education of junior scientists and outreach to the public and implement our Plan for Enhancing Diverse Perspectives (PEDP) Specific Aim 6. Resolve conflicts and maintain succession planning, and Specific Aim 7. Provide financial and administrative support. This core will coordinate the activities of the other three cores. Core B will maintain the HS rat colony, and will expand its scope to also distribute RATTACA rats, which are HS rats with genetically predicted phenotypes. Core C will provide genotyping of HS rats, and genome-wide association studies (GWAS), expression quantitative trait loci (eQTL) mapping and other genetic analyses. Core D will fund Pilot Projects to promote the use of the services offered by this center and to continue to support the ecosystem that has developed over the past decade.