The diabetes genetics community recently met in California to discuss the impact that the latest findings in susceptibility mapping might have on our understanding of the pathophysiology of diabetes mellitus and its long-term complications. Organized by Ralph DeFronzo (San Antonio, TX) and Alan Permutt (St Louis, MO) the symposium covered the genetics of type 1 and type 2 diabetes, obesity, approaches to population selection and stratification, quantitative trait analysis, epidemiological tools and technological advances in genotyping.