DPP4 and diabetes mellitus: Milk-derived antidiabetes peptides could treat diabetes by inhibiting dipeptidyl peptidase-IV (DPP-IV), α-glucosidase, and α-amylase, but only the antidiabetes peptides RPKHPIK (RK7) and KVLPVPQ (KQ7), which could inhibit α-amylase, have been identified in yak milk casein [16].