CECR1, also known as adenosine deaminase CECR1 isoform, is a member of a family of adenosine deaminase-related growth factors. Adenosine deaminase is one of the key enzymes of purine nucleotide metabolism. CECR1 is a secreted protein that is expressed in many tissues, with the highest expression in lymphoblasts, heart, lung, and placenta. Recombinant human CECR1, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.