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, or monocytes. Recombinant Murine I-TAC is a 9.0 kDa protein containing 79 amino acid residues, including the four highly conserved cysteine residues present in CXC chemokines.