Chemokines are a subclass of cytokine proteins that act as signalling molecules and mediators in chemotaxis. The proteins are characterized as low molecular weight, 3-D structured; CXC, CC, CX3C, and XC residues. Chemokine proteins are often studied for their roles in regulating immune and inflammatory responses via cell migration properties and the localization of target cells such as leucokytes. Their bioactivity is achieved by signalling through G protein-coupled chemokine receptors. kbDNA offers a library of both bacterial and mammalian expressed recombinant chemokines with biotinylated options.