FGF21, also known as fibroblast growth factor 21, is a member of the fibroblast growth factor family. It has a hydrophobic amino terminus, which is a typical signal sequence, and appears to be a secreted protein. It stimulates glucose uptake in differentiated adipocytes via the induction of glucose transporter SLC2A1/GLUT1 expression. Recombinant mouse FGF21, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.