To decipher the mechanism of inosine-mediated thermogenesis, the authors investigated the inosine importer ENT1, encoded by Slc29a1. Lack of ENT1 or pharmacological inhibition of ENT1 with dipyridamole replicated the thermogenic effect of inosine.1 These mechanisms were also present in human adipocytes, and ENT1 was linked to human obesity on multiple levels.1 These results implicate inosine-derived therapeutics or compounds targeting ENT1 as new weight loss drugs. The gene discussed is SLC29A1; the disease is obesity due to melanocortin 4 receptor deficiency.