In our study, we observed that the coadministration of BC (approved in the United States since 2009 as an adjunctive treatment for type 2 diabetes [40]) and the KOR antagonist PF-04455242 (which was tested in a double-blind study for the treatment of bipolar disorder in 2010 [25,41]) triggered weight loss in our animals. The gene discussed is OPRK1; the disease is type 2 diabetes mellitus.