Topic in Focus
It sounds like a promise of salvation: diseased segments of DNA are cut out using molecular scissors and replaced with healthy segments. That is the basic principle of genome editing. Yet these new methods are also controversial. While robust, high-yield crops can help combat famine, concerns are also growing about their unpredictable impact on the environment. New cures and treatment methods raise questions about the possible long-term effects of interventions to the germ-line.