SO ENDS this section on the relationship between gene sequence and function. In the early days of gene cloning, when it was generally thought that if you cloned a disease gene and knew its protein product, such as dystrophin in Duchenne muscular dystrophy, then the path to a therapy was straightforward. It was not: it was contextual, how that protein is located and interacting in the cell. And in this case, assigning function to a pure gene sequence was thought to be an easy step. But similarly, the story turned out to be much more complex.