We are indebted to the radioimmunoassay core of the Penn Diabetes and Endocrinology Research Center (National Institute of Diabetes and Digestive and Kidney Diseases grant P30 DK19525) for assistance with resistin assays, the Immunology Core of the University of Pennsylvania Center for AIDS Research for peripheral blood monocytes, and the University of Pennsylvania General Clinical Research Center (National Institutes of Health grant M01RR00040) and its nursing staff for outstanding patient care. The gene discussed is RETN; the disease is diabetes mellitus.