In the intervening years, there have been other types of agents approved for treating type 2 diabetes, including DPP4 inhibitors, SGLT2 inhibitors, and GLP1 receptor agonists, all of which have been introduced as second line agents after the treatment failure of diet, exercise, and metformin to adequately treat type 2 diabetes [15]. Here, DPP4 is linked to type 2 diabetes mellitus.