However, the net impact of HTLV-I/HIV-I co-infection on HIV disease is still controversial (8, 22). It seems that introduction of highly active antiretroviral therapy (HAART), has been led to longer survival for HIV-infected individuals and stops HIV replication, but does not have any protective impact on HTLV proviral load, CD4 cell count and HAM/TSP development (18-19, 23-25). The gene discussed is CD4; the disease is tropical spastic paraparesis.