NOS1AP and type 2 diabetes mellitus: Based on the facts that PPARD and NOS1AP play crucial roles in functional regulation of β-cells, insulin resistance and metabolism, we conduct this study to identify the association PPARD rs2016520 (T/C) and NOS1AP rs12742393 (A/C) polymorphisms with therapeutic efficacy of nateglinide in Chinese patients with T2DM.