( ( A cytokine ) ( ( is ( a ( cell-signaling ( protein molecule ) ) ) ) . ) )
(ROOT (S (NP (DT A) (NN cytokine)) (VP (VBZ is) (NP (DT a) (JJ cell-signaling) (NN protein) (NN molecule))) (. .)))
A cytokine is a cell-signaling protein molecule.
(ROOT (S (NP (NNPS Proteins)) (VP (VBP are) (NP (NP (JJ complex) (JJ organic) (NNS molecules)) (SBAR (WHNP (WDT that)) (S (VP (VBP make) (PRT (RP up)) (NP (NNS cells))))))) (. .)))