RARRES2, also known as chemerin, is a secreted chemotactic protein that initiates chemotaxis via the ChemR23 G protein-coupled seven-transmembrane domain ligand. Expression of this gene is upregulated by the synthetic retinoid tazarotene and occurs in a wide variety of tissues. The active protein has several roles, including that as an adipokine, and is truncated on both termini from the proprotein. Recombinant human RARRES2 protein, fused to His-tag at N-terminus, was expressed in E.coli.