We inherit genes from each parent. Genes provide instructions for our bodies. Genes, environment, and behavior interact to influence disease risk. We study the genetics of type 2 diabetes and obesity. We specifically study how genes influence these conditions among Pima Indians in Arizona. Pima Indians have high rates of obesity. They also have the highest incidence of type 2 diabetes in the world. We compare the genetic details of Pima Indians with and without obesity and type 2 diabetes. Our research identifies genes and genetic variations associated with these conditions. Our studies help explain how genes, environment, and behavior interact in these conditions.