I-TAC is a 'non-ELR' CXC chemokine that is regulated by interferon and signals through the CXCR3 receptor. I-TAC is chemoattractant for IL-2 activated T cells, but does not affect freshly isolated un-stimulated T cells, neutrophils, ormonocytes. Recombinant Human I-TAC (CXCL11) is an 8.3 kDa protein containing 73 amino acid residues, including the four highly conserved cysteine residues present in CXC chemokines.?