The inhibitory effect of Cy-3-glucoside on retinol-binding protein 4 (RBP4) expression and the enhancing effect on glucose transporter 4 (Glut4) in the adipose tissue were highlighted in KK-A(y) type 2 diabetes mice after a diet with 0.2% anthocyanin for 5 weeks [194]. This evidence concerns the gene RBP4 and type 2 diabetes mellitus.