Can marine snails lead to better insulins for human use? Could be.
It seems that the cone snail uses a type of insulin as a weapon. It drops the blood sugar of the fish they hunt so quickly that the fish become paralyzed. And a new insulin for humans has been based on the cone snail insulin. It's not yet commercially available.
Of course, there are already relatively fast acting insulins like Humalog, Novolog, and Apidra, but they take about 15 minutes to start working. The goal with the snail-type insulin would be to have it start working even sooner.
Human insulin tends to associate into hexamers, and then it has to dissociate from these clusters. The snail insulin doesn't form these clusters, so it can act much faster.
The full text has more details, but it's behind a paywall for those without institutional access.