yos that are genetic copies of living people to make stem cells, which may help treat many diseases but also raises concerns about human cloning. By Melissa Healy, Los Angeles Times 5:43 PM PDT, May 15, 2013 Advertisement <a target="_blank" href="http://ad.doubleclick.net/click%3Bh%3 Dv8/3de4/3/0/%2a/1r%3B272