To reveal whether it is each drug effect or a drug class effect of DPP-4 inhibitors, we investigated the effects of treatment with the DPP-4 inhibitors anagliptin and sitagliptin for a relatively long period on FABP4 level in patients with type 2 diabetes mellitus at a high risk for cardiovascular events who were on statin therapy as a real-world setting. The gene discussed is DPP4; the disease is diabetes mellitus.