Mice with targeted global disruption of the GHR gene (GHRKO mice) are excellent models of LS, presenting an obese, growth-retarded phenotype with low levels of IGF-1 and insulin, high levels of GH, and enhanced resistance to diabetes and cancer (2, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42). This evidence concerns the gene GH1 and diabetes mellitus.