DDR2, also known as discoidin domain-containing receptor 2, belongs to the discoidin-like domain containing subfamily of receptor tyrosine kinases. It is mainly expressed in mesenchymal cells and is unique amog RTKs in that its ligand is fibrillar collagen rather than a growth factor-like peptide. Recombinant human DDR2, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.