The OD values of the OB-Rb mRNA expression in hypothalamus in the control, DIO4W, DIO8W, and T2DM groups were 29.15 ± 7.96, 14.89 ± 4.98, 5.96 ± 2.12 and 5.61 ± 1.13, respectively, which showed a downward trend (P < 0.01) (Fig. 5). This evidence concerns the gene RB1 and type 2 diabetes mellitus.