CXCL9 and tropical spastic paraparesis: Altogether, this evidence infers that, during HAM-TSP development model, HTLV-1-infected cells in the CNS may produce large amounts of IFN-γ that can induce resident macrophages, DCs, neutrophils and astrocytes to secrete MCP-1, MIP-1α/β, RANTES, CXCL9, and CXCL10 chemokines among others (7, 93–95).