It has been suggested that a strong antiviral cytotoxic T lymphocytes (CTL) response is initiated by individuals with this HLA type by virtue of its high binding affinity to the Tax (residues 11–19) peptide, resulting in targeted killing of HTLV-I-infected cells and a subsequent low proviral DNA load, thus can protect the infected subject from HAM/TSP. Here, CNTN2 is linked to tropical spastic paraparesis.