Darwin's Radio: Prehistoric Gene Reawakens to Battle HIV

http://www.dailygalaxy.com/my_weblog/2009/04/by-annalee-newitz-500-pm-on-mon-apr-27-2009-10350-views-edit-post-set-to-draft-slurpcopy-this-whole-post-to-another-s.html

About 95% of the human genome has once been designated as "junk" DNA. While much of this sequence may be an evolutionary artifact that serves no present-day purpose, some junk DNA may function in ways that are not currently understood. The conservation of some junk DNA over many millions of years of evolution may imply an essential function that has been "turned off." Now scientists say there's a junk gene that fights HIV. And they've discovered how to turn it back on.