Following the recognition that GLP‐1 serves as an incretin, various incretin or GLP‐1‐based drugs including GLP‐1 receptor (GLP‐1R) agonists (GLP‐1RAs) and dipeptidyl peptidase‐4 inhibitors (DPP‐4i) have been developed for treating type 2 diabetes (T2D). This evidence concerns the gene GLP1R and type 2 diabetes mellitus.