Jon Cohen
New findings from antibody tests strengthen earlier claims that a new herpesvirus is the cause of Kaposi's sarcoma (KS), a tumor famous for the purple skin splotches that 20% of HIV-infected gay men develop. But not everybody is convinced that the work, by teams at Columbia University and the University of California, San Francisco, proves causality. Among the unanswered questions is why the virus is found predominantly among gay men, while other human herpesviruses are widespread in the general population.