HIV in semen: Still more to be learned

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. In 1983, during the earliest days of AIDS research, Deborah Anderson and her colleagues in Boston, Massachusetts hypothesized that AIDS was transmitted by virallyinfected "Trojan horse leukocytes " in semen [1]. This prediction has been supported by numerous studies over the past two decades, although many questions remain concerning HIV infection of the male genital tract. In this issue of AIDS Research and Therapy, the Anderson group presents an important research tool to help address some of the critical unanswered questions in this area [2]. A series of salient studies have shaped current concepts on HIV-1 in semen. In 1984, Ho et al. described retroviral particles and infected cells in the semen of a homosexual man with AIDS [3]. Shortly thereafter Stewart et al.