
In this January 2013 photo provided by Penn Medicine, a technician removes a case of modified T cells genetically modified to resist HIV infection from storage in an ultra-low temperature freezer for testing at the Perelman School of Medicine in Philadelphia. Scientists have modified genes in the blood cells of HIV patients to help them resist the AIDS virus, and say the treatment seems safe and promising. The results give hope that this approach might one day free at least some people from needing medicines to keep HIV under control. Results of the study at the University of Pennsylvania were published in the Thursday, March 6, 2014 issue of the New England Journal of Medicine. (AP Photo/Penn Medicine, Peggy Peterson Photography) AP Photo/Penn Medicine, Peggy Peterson Photography