CD93, also known as complement component C1q receptor, belongs to a family of transmembrane glycoproteins which also includes endosialin and thrombomodulin. It is involved in various aspects of inflammatory reactions. CD93 is expressed by vascular endothelial cells and by a variety of hematopoietic cells. It is receptor for C1q, mannose-binding lectin (MBL2) and pulmonary surfactant protein A (SPA). Recombinant human CD93, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.