( ( Mutations ( in ( ( regulatory genes ) ( that ( normally ( control ( the ( cell cycle ) ) ) ) ) ) ) ) ( ( cause cancer ) . ) )
(ROOT (S (NP (NP (NNS Mutations)) (PP (IN in) (NP (NP (JJ regulatory) (NNS genes)) (SBAR (WHNP (WDT that)) (S (ADVP (RB normally)) (VP (VBP control) (NP (DT the) (NN cell) (NN cycle)))))))) (VP (VBP cause) (NP (NN cancer))) (. .)))
Mutations in regulatory genes that normally control  the cell cycle cause cancer.
(ROOT (S (NP (NP (NNS Mutations)) (PP (IN in) (NP (NP (JJ regulatory) (NNS genes)) (SBAR (WHNP (WDT that)) (S (ADVP (RB normally)) (VP (VBP control) (NP (DT the) (NN cell) (NN cycle)))))))) (VP (VBP cause) (NP (NN cancer))) (. .)))