Since HAM/TSP patients had higher antibody responses for HTLV-1 virus proteins, Gag, Env and Tax, in serum [11], we next analyzed antibody responses for HTLV-1 antigens in CSF and serum of HAM/TSP patients and ACs to examine whether HTLV-1-specific antibody synthesis is associated with ASC in CSF of HAM/TSP patients. This evidence concerns the gene ERVW-1 and tropical spastic paraparesis.