Human retroviruses: their role in neoplasia and immunodeficiency.

Human retroviruses (HTLVs and HIVs) infect the cells of the immune system and cause mild-to-severe immune dysfunction. They are directly or indirectly responsible for associated neoplasia and central nervous system disorders. The study of these viruses is of great importance, not only because they cause grave illnesses like AIDS, neoplasias, and CNS disease, but also because they have the ability to exert such fine levels of gene regulatory control in their replication and expression. These studies will ultimately shed light on fundamental mechanisms of genetic control in human cells in their normal state and the alterations of these controls in neoplastic or immunologically aberrant states.