Although an observational and retrospective study by Giagulli and colleagues on hypogonadal patients with T2DM showed that testosterone replacement therapy (TRT), when given together with weight-reducing anti-hyperglycemic compounds (in particular, GLP1-Ra), was effective not only in maintaining stable serum TT levels in the normal range for young healthy men but also in reducing hyperglycemia and hyperlipidemia to achieve their treatment targets, and in reducing weight to considerably ameliorate the severity of erectile dysfunction [21]. The gene discussed is GCG; the disease is erectile dysfunction.