( PIN ( ( consists ( of ( proliferation ( of ( ( prostatic ( epithelial cells ) ) ( within ( preexisting glands ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP PIN)) (VP (VBZ consists) (PP (IN of) (NP (NP (NN proliferation)) (PP (IN of) (NP (NP (JJ prostatic) (JJ epithelial) (NNS cells)) (PP (IN within) (NP (VBG preexisting) (NNS glands)))))))) (. .)))
PIN consists of proliferation of prostatic epithelial cells within preexisting glands.
(ROOT (S (NP (NNS Cells)) (VP (VBP come) (PP (IN from) (NP (VBG preexisting) (NNS cells)))) (. .)))