Muscle atrogenes such as MuRF1/Trim63 and Atrogin1/Fbxo32 were downregulated in ob/ob GRfl/fl mice compared with lean GRfl/fl mice (Supplemental Figure 11C), possibly reflecting the counteracting role of hyperinsulinemia in ob/ob mice for maintaining muscle mass. This evidence concerns the gene FBXO32 and hyperinsulinism.