Analysis of the epididymal fat pads of wild type C57BL/6J mice, a meaningful indicator of obesity-related diabetes, revealed an increase in GPR21 expression, which trended towards significance, in HFHS-fed mice (Fig. 1a), with a concurrent elevation in the macrophage marker F4/80 (Fig. 1b). The gene discussed is GPR21; the disease is diabetes mellitus.