Chemokine (C-X-C motif) ligand 11 (CXCL11) is a small cytokine belonging to the CXC chemokine family that is also called Interferon-inducible T-cell alpha chemoattractant (I-TAC) and Interferon-gamma-inducible protein 9 (IP-9). CXCL11 is strongly induced by IFN-γ and IFN-β, and weakly induced by IFN-α. It is chemotactic for interleukin-activated T-cells but not unstimulated T-cells, neutrophils or monocytes.