This point is well illustrated by glucagon-like peptide 1 receptor (GLP1R), which is likely exerting effects on bodyweight and glycemic control through distinct mechanisms.9 As such, selecting genetic variants in the GLP1R region based on their statistical association with type 2 diabetes mellitus liability may only allow for the investigation of effects mediated through mechanisms of glycemic control and exclude those related to other GLP1R effects, such as lowering body weight. The gene discussed is GLP1R; the disease is type 2 diabetes mellitus.