ABSTRACT The Center of Comparative Medicine and Pathology (CCMP) supports animal model use in cancer research through its Research Animal Resource Center (RARC) and Laboratory of Comparative Pathology (LCP). At MSK, animal models are used in basic and applied investigational studies as well as for training of both clinical and research staff. Animals are employed in diverse areas including the development of new methods for diagnosis and treatment of cancer as well as the elucidation of the basic biological mechanisms resulting in neoplasia. CCMP’s professional and paraprofessional staff (163 FTE) serve as a consultative and technical resource for MSK investigators on all matters related to animal research. RARC comprises five sections: 1) Aquatic Systems and Services; 2) Biosecurity; 3) Education and Quality Assurance (EQA); 4) Husbandry and Operations (H&O); and, 5) Veterinary Services (VS). RARC provides housing for and humane care to over 170,000 animals daily, utilized by 122 investigators. RARC’s oversight of MSK’s AAALAC-accredited, centrally managed animal care program ensures the efficient use of available space and staff resources and allows for close professional monitoring of the animal research program. Aquatic Systems and Services maintain the housing systems and provide husbandry and technical services in support of MSK’s zebrafish colonies. Biosecurity ensures that MSK’s rodent colonies remain pathogen free by routinely surveying colony health and quarantining incoming rodents from vendors. EQA administers an extensive educational program that provides training to animal care and research staff via didactic and hands-on sessions, web-based tutorials, as well as written instructional materials. RARC’s H&O section operates two specialized state-of-the-art facilities encompassing ~73,700 net square feet of space that provide critical environments and the specialized equipment necessary for the maintenance and use of a variety of animal models. VS’s staff ensures that all animals receive appropriate clinical care and perform technical procedures for research staff. The LCP, a multi- disciplinary pathology laboratory, and its Genetically Engineered Animal (GEA) Phenotyping Service, support individual laboratory’s research and RARC’s programs by providing clinical and anatomic pathology services and extensive phenotypic profiles of GEA.