Stafford Stafford S S Elahi Elahi D D Meneilly Meneilly GS GS Effect of the dipeptidyl peptidase-4 inhibitor sitagliptin in older adults with type 2 diabetes mellitus Effect of the dipeptidyl peptidase-4 inhibitor sitagliptin in older adults with type 2 diabetes mellitus J Am Geriatr Soc J Am Geriatr Soc 2011 2011 10.1111/j.1532-5415.2011.03438.x 10.1111/j.1532-5415.2011.03438.x supplied-pmid 21668924? The gene discussed is DPP4; the disease is diabetes mellitus.