Oral administration of Inonotus obliquus polysaccharides in a high fat diet and STZ-induced type 2 diabetic mice significantly reduced fasting blood glucose levels and up-regulated protein expressions of PI3K-p85, p-Akt (ser473) in liver, and GLUT4 in adipose tissue. The gene discussed is SLC2A4; the disease is type 2 diabetes mellitus.