So, in addition to being source material for special effects in "The Abyss," ctenophores now seem to have evolved nerves and a nerve network independently from other animals, using different genes and enzymes.
There seems to be a lot of conclusion-leaping in this article (for example, I'm not sure how many conclusions you can draw about ways a brain can evolve by looking at an animal that dopes not have a brain) and a click-baitish headline, but still an interesting read.
https://aeon.co/essays/what-the-ctenophore-says-about-the-evolution-of-intelligence