Until now, scientists have had a tough time getting therapeutic genes to go where they need to go. iStockphoto.com hide caption toggle caption iStockphoto.com Shots - Health News Scientists Modify T-Cells To Attack Leukemia August 11, 2011 Gene therapists are looking for persistence. They want the therapeutic gene to stick around and help T-cells fight cancer cells. And in two new reports, that's what they got. But don't expect to find the treatment at a hospital near you any time soon.