PHYSorg.com: PHYSorg news tagged with: nk cells http://www.physorg.com/ en-us Physorg.com internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. Some of your body's cells have a 'license to kill' Millions of "natural killer cells" -- nature's first line of defense against cancer, viruses and other infectious microbes --- are on constant patrol inside your body. http://www.physorg.com/news154541184.html Medicine & Health Sun, 22 Feb 2009 16:07:11 EST news154541184