cytotoxin vs toxin

cytotoxin and toxin both are nouns.

Word	Noun	Adjective	Verb	Adverb
cytotoxin	Yes	No	No	No
toxin	Yes	No	No	No

As nouns, toxin is a hypernym of cytotoxin; that is, toxin is a word with a broader meaning than cytotoxin:

cytotoxin: any substance that has a toxic effect on cells
toxin: a poisonous substance produced during the metabolism and growth of certain microorganisms and some higher plant and animal species

cytotoxin (noun)	toxin (noun)
any substance that has a toxic effect on cells	a poisonous substance produced during the metabolism and growth of certain microorganisms and some higher plant and animal species