( ( Cancer cells ) ( ( ( are not ) ( able ( to ( undergo apoptosis ) ) ) ) . ) )
(ROOT (S (NP (NNP Cancer) (NNS cells)) (VP (VBP are) (RB not) (ADJP (JJ able) (S (VP (TO to) (VP (VB undergo) (NP (NNS apoptosis))))))) (. .)))
Cancer cells are not able to undergo apoptosis.
(ROOT (S (S (NP (DT All) (NNS cells)) (VP (VBP undergo) (NP (NN cell) (NN division)) (PP (IN during) (NP (DT a) (NN lifetime))))) (, ,) (CC but) (S (SBAR (WHADVP (WRB when)) (S (NP (DT this) (NN process)) (VP (VBZ is) (ADVP (RB out)) (PP (IN of) (NP (NN control)))))) (, ,) (NP (NN cancer)) (VP (VBZ results))) (. .)))