nephrotoxin vs toxin

nephrotoxin and toxin both are nouns.

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

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

nephrotoxin: any toxin that affects the kidneys
toxin: a poisonous substance produced during the metabolism and growth of certain microorganisms and some higher plant and animal species

nephrotoxin (noun)	toxin (noun)
any toxin that affects the kidneys	a poisonous substance produced during the metabolism and growth of certain microorganisms and some higher plant and animal species