Many types of genetic engineering have yielded clear benefits with few apparent risks. However, many emerging applications of genetic engineering are much more controversial, often because their pote...Many types of genetic engineering have yielded clear benefits with few apparent risks. However, many emerging applications of genetic engineering are much more controversial, often because their potential benefits are pitted against significant risks, real or perceived. This is certainly the case for gene therapy, a clinical application of genetic engineering that may one day provide a cure for many diseases but is still largely an experimental approach to treatment.