IFN-γ producing HTLV-1-infected CD4+ T cells stimulated astrocytes to secrete the chemokine CXCL10 (IP-10), a ligand of CXCR3 [65] and suggest that CXCL10 from astrocytes might recruit additional HTLV-1-infected CXCR3+CD4+ T cells into the CNS of HAM/TSP patients. This evidence concerns the gene CXCL10 and tropical spastic paraparesis.