 Tetrodotoxin, TTX, a powerful sodium channel inhibitor, is a natural toxin found in certain species of marine animals such as pufferfish. It can cause severe illness or death if consumed by humans and has recently been detected in other areas of the world including the Pacific and Mediterranean. Despite its lethality, there is currently no known antidote for TTX. This article was authored by Vaishali Bain, Mary Lahain, Madhura Madhikshit and others.