To evaluate the effects of PPARD and NOS1AP variations on the efficacy of nateglinide, 60 newly diagnosed T2DM patients with various PPARD rs2016520 (C/T) and NOS1AP rs12742393 (A/C) genotypes but with the same SLCO1B1 T521C and CYP2C9*1 genotype were enrolled. The gene discussed is PPARD; the disease is type 2 diabetes mellitus.