This study aimed to investigate the levels of Retinol Binding Protein 4 (RBP4), Lipocalin-2, and high-sensitivity C-reactive protein (hsCRP) in individuals with impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM). This evidence concerns the gene RBP4 and type 2 diabetes mellitus.