( DNA ( ( ( ( damage and ) repair ) ( in ( ( ( human lymphocytes ) and ) ( leukocytes ( ( Palus et ) al. ) ) ) ) ) . ) )
(ROOT (S (NP (NNP DNA)) (VP (VBP damage) (CC and) (VBP repair) (PP (IN in) (NP (NP (JJ human) (NNS lymphocytes)) (CC and) (NP (NNP leukocytes) (NNP Palus) (CC et) (NNP al.))))) (. .)))
DNA damage and repair in human lymphocytes and leukocytes Palus et al.
(ROOT (S (S (NP (DT The) (JJ human) (NN body)) (VP (VBZ has) (NP (QP (RB as) (JJ many) (IN as) (CD two) (CD trillion)) (NNS lymphocytes)))) (, ,) (CC and) (S (NP (NNS lymphocytes)) (VP (VBP make) (PRT (RP up)) (NP (NP (QP (RB about) (CD 25)) (NN %)) (PP (IN of) (NP (NP (DT all)) (PP (IN of) (NP (NNS leukocytes)))))))) (. .)))