Promising news in the fight against HIV/AIDS: Scientists may be seeing progress in the effort to use gene therapy to fight the virus that causes the disease. After inserting human stem cells into mice, researchers discovered that the cells multiplied into immune cells that provided protection against HIV infection. "That's like nature telling us how to cure AIDS," said Paula Cannon, one of the study’s co-authors. The idea is "to engineer a patient's own cells so they'd be resistant to HIV." The process, which has only been conducted on mice so far—research on humans won’t be done for another four years—was written about in Nature Biotechnology.