Research and discovery of the first human cancer virus, HTLV-1

Human T-cell lymphoma virus (HTLV)-1 was the first human retrovirus to be discovered. It has been recognized as the cause of adult T-cell leukemia (ATL). In addition to giving a historical perspective on HTLV-1 and other retrovirus research, this paper discusses the origin of HTLV-1; the modes of transmission and global epidemiology of HTLV-1 infection; the genome of HTLV-1 and the mechanism of HTLV-1-induced leukemogenesis; the role of HTLV-1 in other diseases, and recent breakthroughs in ATL therapy.