( ( Mutations ( that ( lead ( to cancer ) ) ) ) ( usually ( ( occur ( in ( genes ( that ( control ( the ( cell cycle ) ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (NP (NNS Mutations)) (SBAR (WHNP (WDT that)) (S (VP (VBP lead) (PP (TO to) (NP (NN cancer))))))) (ADVP (RB usually)) (VP (VBP occur) (PP (IN in) (NP (NP (NNS genes)) (SBAR (WHNP (WDT that)) (S (VP (VBP control) (NP (DT the) (NN cell) (NN cycle)))))))) (. .)))
Mutations that lead to cancer usually occur in genes that control the cell cycle.
(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))) (. .)))