CENTER OVERVIEW: Abstract For 35 years, the NIDDK-funded Diabetes Research Center (DRC) at Joslin has successfully fostered break- through discoveries in the field and rapidly translated advances into new strategies for prevention, treatment and cure of diabetes and its complications. The DRC has catalyzed extensive collaborative basic and clinical diabetes research at Joslin, Harvard Medical School (HMS) and other Massachusetts research institutions, bringing together interdisciplinary expertise to address challenges in diabetes and related metabolic diseases. During the past five years, publications by the Joslin DRC Research Base have led to paradigm-changing ideas on the pathogenesis and treatment of various types of diabetes. Success in making these discoveries has been accelerated by state-of-the-art technological resources and expertise of the Joslin DRC Biomedical Research Cores and our program design that nimbly incorporates advances in the field. The Pilot & Feasibility Program has successfully attracted and engaged early stage investigators who have stayed in the diabetes field and competed successfully for NIH support. The Enrichment Program is the most extensive diabetes and metabolic disease educational program for post-doctoral fellows, students and investigators in the Harvard Medical School area, jointly supported by the Joslin DRC and institutional funding. In this competing renewal application, we summarize growth of the Joslin Research Base, contributions by Joslin investigators to the diabetes field, and the innovations that have been made in each component of our DRC program. We propose exciting new directions for the Joslin DRC that will continue to accelerate scientific discoveries in fields of diabetes and metabolism over the next five years.