With the advent of sitagliptin (MK-0431) and vildagliptin (LAF-237), doubt no longer exists regarding the potential of dipeptidyl peptidase IV (DPP-IV; CD26; E.C. 3.4.14.5) inhibitors for the treatment of type 2 diabetes [1-4]. Here, DPP4 is linked to type 2 diabetes mellitus.