The Animals Models Core represents an expanded version of the former Toxicology Core. Previous work of the Core focused on animal studies to assess toxicity of vectors in support of clinical trials and basic toxicologic research in nonhuman primates. We found that the majority of the activities of this Core were directed at addressing basic research questions. We therefore have broadened the scope of the core to support the preclinical evaluation of molecular therapies in a variety of animal models and have changed the name of the core to reflect its new mission. The foundation of the Animal Models Core is the Animal Services Unit (ASU) which provides comprehensive support in a number of animal models with a focus on mice, rats, rabbits, guinea pigs and nonhuman primates. The ASU operates a rodent facility with approximately 4000 cages and a nonhuman primate facility whose census averages 50 to 60 rhesus and cynomolgus macaques. The ASU staff provides technical, husbandry, facility, clinical and enrichment support. The Nonhuman Primate Research Program works directly with faculty to design, conduct and perform experiments in nonhuman primates. This application requests resources to support technical services for rodent, rabbit, canine and feline experiments as well as partial support for pilot experiments in nonhuman primates.