( We ( ( are ( studying ( amplification ( of ( ( a region ) ( of ( chromosome 20 ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP We)) (VP (VBP are) (VP (VBG studying) (NP (NP (NN amplification)) (PP (IN of) (NP (NP (DT a) (NN region)) (PP (IN of) (NP (NN chromosome) (CD 20)))))))) (. .)))
We are studying amplification of a region of chromosome 20.
(ROOT (NP (NP (JJ Duplications) (PRN (-LRB- -LRB-) (CC or) (ADJP (JJ amplifications)) (-RRB- -RRB-)) (NN lead)) (PRN (-LRB- -LRB-) (PRP s) (-RRB- -RRB-)) (PP (TO to) (NP (NP (JJ multiple) (NNS copies)) (PP (IN of) (NP (DT a) (JJ chromosomal) (NN region))))) (. .)))