In contrast, the overexpression of the MAX dimerization protein MLX (MLX) gene, regenerative family member 4 (REG4) gene, pseudopodium-rich atypical kinase 1 (PEAK1) gene, potassium inward rectifying channel subfamily J member 11 (KCNJ11) gene, and major histocompatibility complex class II DRβ5 (HLA-DRB5) gene is positively correlated with the risk of T2DM (OR values all>1). This evidence concerns the gene REG4 and type 2 diabetes mellitus.