CLINICAL TRANSLATIONAL RESEARCH CORE: Abstract The Joslin Clinical Translational Research Core (CTRC) provides infrastructure for the conduct of high-quality clinical and translational research in diabetes and metabolism. This is done by facilitating access to appropriate patient populations as well as providing specialized facilities and expertise focused on clinical research related to the pathophysiology, prevention and treatment of diabetes, its complications, and related metabolic disorders. Since it was established in the last funding cycle, the CTRC has provided consultative services for study design and regulatory guidance. Physical infrastructure and well-trained nusing and technical staff assist investigators in safely carrying out gold standard euglycemic, hyperglycemic, and hypoglycemic clamps at physiologic or pharmacologic insulin concentrations; intravenous and oral glucose and mixed meal tolerance tests; and other metabolic testing to assess insulin secretion, insulin action, and other physiologic processes for patient-centered research specific to diabetes and metabolism. In addition expertise and equipment are available for exercise training and testing capacities, dual-energy X-ray absorptiometry for assessment of bone density and body composition, electroretinogram and optical coherence tomography angiography for visualization of retinal function and vasculature, continuous glucose monitor data analayses, cooling vests for brown fat activation, metabolic assessments, bioimpedance analysis, and anthropometry. CTRC facilities and procedures allow for the sampling of various biologic fluids, performance of pharmacokinetic and pharmacodynamic studies and physiologic measurements, and protocols for skin, muscle and adipose tissue sampling. Additionally, the Core has established a diabetes-specific Biorepository that facilitates discovery of and access to biospecimens and linked data. In this application, we propose to provide resources for “T1” translational research programs with specific focus on prediction, prevention, and interdiction of type 1 or type 2 diabetes and related complications; to facilitate design, implementation, and evaluation of investigator-initiated clinical trials and epidemiologic studies for “T2-T3” research programs focused on improving/optimizing treatments of diabetes and related complications; and to expand the CTRC Biorepository. These represent efforts that will build research capacity for translating new discoveries into improvement in the treatment, prevention and ultimately, the cure of diabetes.