Liao et al. [40] utilized a genome-wide association study (GWAS)-based approach to find candidate genes affecting therapeutic responses to DPP-4 inhibitors in 171 Taiwanase patients with T2D receiving sitagliptin (n = 114), saxagliptin (n = 22), vildagliptin (n = 23), or linagliptin (n = 12) therapy for at least 60 days. Here, DPP4 is linked to type 2 diabetes mellitus.