cytokine vs lymphokine

cytokine and lymphokine both are nouns.

Word	Noun	Adjective	Verb	Adverb
cytokine	Yes	No	No	No
lymphokine	Yes	No	No	No

As nouns, lymphokine is a hyponym of cytokine; that is, lymphokine is a word with a more specific, narrower meaning than cytokine:

cytokine: any of various protein molecules secreted by cells of the immune system that serve to regulate the immune system
lymphokine: a cytokine secreted by helper T cells in response to stimulation by antigens and that acts on other cells of the immune system (as by activating macrophages)

Other hyponyms of cytokine include TNF, tumor necrosis factor, tumour necrosis factor.

cytokine (noun)	lymphokine (noun)
any of various protein molecules secreted by cells of the immune system that serve to regulate the immune system	a cytokine secreted by helper T cells in response to stimulation by antigens and that acts on other cells of the immune system (as by activating macrophages)