Yessotoxin is a type of toxin produced by dinoflagellates, which are a kind of marine planktonic microorganisms. They are capable of causing poisoning in humans when they consume seafood that has been contaminated with this toxin. There are several synonyms for yessotoxin, including YTX, YTX1, and NSP2. YTX is a shorthand notation for yessotoxin, while YTX1 is a variant of YTX. NSP2 is a type of neurotoxin produced by dinoflagellates that exhibits similar effects to those of yessotoxin. These synonyms are used interchangeably to refer to the same class of toxins and are important in understanding the mechanisms of toxin production and the potential risks posed by consuming contaminated seafood.