Science Daily — Researchers at the University of Pennsylvania School of Medicine are the first to show that a mouse protein, whose human equivalent is related to defense against HIV-1, inhibits the infection and spread of a mouse tumor virus. The study, which appeared online January 28 in advance of its print publication in Nature, provides a new model for the discovery and evaluation of anti-HIV drugs. HIV-1, like the mouse tumor virus, is a retrovirus which infects immune system cells. However, unlike HIV-1, the mouse virus causes breast cancer in mice.>>> Discuss This Story