ssOpen AcceReview The HBZ gene, a key player in HTLV-1 pathogenesis

Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATL) and is also associated with a variety of lymphocyte-mediated diseases. The HTLV-1 basic leucine zipper (HBZ) gene, found to be consistently expressed in ATL, has recently been the subject of intensive research efforts. In this review, we summarize recent findings about HBZ and discuss its roles and functions not only in the virus life cycle, but also in HTLV-1 disease pathogenesis. Background Adult T-cell leukemia/lymphoma (ATL) was proposed as a distinct clinical entity in 1975 by Takatsuki et al. [1]. An etiological linkage between ATL and virus infection was suggested by the geographical clustering of ATL patients in southwestern Japan. Subsequently, human T-cell leuke-mia virus type 1 (HTLV-1) was discovered in 1980 as the cause of ATL and was the first retrovirus associated with a disease in humans [2,3]. Early focus on the mechanism o