Altering the genome of an already developed organism, that is as opposed to an egg-cell or an embryo, is, I suppose, much more difficult.  It may be possible though, and if so, it does represent tremendous therapeutic possibilities, but in the grand scheme of things, I believe it&#x27;s less important than the possibility of editing organisms &quot;from scratch&quot;, that is immediately after fecundation (or even before, as I recall an article about using gene editing on sperm cells [1]).  Therapeutic prospects matter to us from a selfish, subjective point of view but from an objective,  anthropological point of view, the idea that we could create organisms with an arbitrary genome is much more significant.<p>1. <a href="http:&#x2F;&#x2F;www.technologyreview.com&#x2F;news&#x2F;543541&#x2F;how-to-really-engineer-a-human-baby&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.technologyreview.com&#x2F;news&#x2F;543541&#x2F;how-to-really-en...</a>