SLC5A2 and type 2 diabetes mellitus: In db/db mice, an animal model of T2D, although tofogliflozin treatment improved hyperglycemia, the body weight was paradoxically increased as compared with the untreated control group,28 which was possibly due to preserved insulin secretion in the tofogliflozin group, similarly to other SGLT2 inhibitors.29 Thus, it is difficult to evaluate the mechanisms of body weight reduction with SGLT2 inhibitors when using diabetic animal models with dysfunctional insulin secretion.