Unprecedented therapeutic challenges the retroviral life cycle and genetic plasticity of human immunodeficiency virus 1 (HIV-1). Twelve years into the HIV epidemic, satisfactory treatment remains elusive. Researchers are understanding AIDS pathogenesis calls for early intervention with antiviral agents. Although still in its infancy, human gene therapy holds considerable potential for the long-term treatment of genetic disorders, cancer and chronic infectious diseases. Gene therapy for HIV infection is receiving particularly intensive study: approaches that are in development include both immunotherapy (e.g. therapeutic vaccines and adoptive transfer of CD8+ T-cell clones) and direct antiviral therapy (intracellular immunization).