[HTLV research 30th year].

This year is 30th year since HTLV was first reported as a causative agent for ATL. From a series of extensive studies especially by Japanese researches, a variety of information is now available, such as characteristics of the virus, regulation of viral and/or cell gene expression by HTLV-encoded protein Tax and Rex, the pathway of activation machinery on cell growth, the mechanism of cell-to-cell transmission, and prevalence of HTLV carries. However, it remains unsolved how HIV-1 invades and enters into human, how HIV-1 replicates in vivo, how the tumor cells are selected during course of infection, and which cellular molecules contribute disease onset and progression. It was thought the mechanism of HTLV-related diseases, ATL and HAM, would be quickly revealed earlier time after HTLV discovery since the HTLV-related diseases show unique characteristics. Nevertheless, we do not have yet satisfied knowledge of the pathogenesis mechanism as well as the treatment. I describe the history and perspective.