( Sunlight ( ( ( does not ) ( cause ( skin cancer ) ) ) . ) )
(ROOT (S (NP (NNP Sunlight)) (VP (VBZ does) (RB not) (VP (VB cause) (NP (NN skin) (NN cancer)))) (. .)))
Sunlight does not cause skin cancer.
(ROOT (S (NP (NNP Sunlight)) (VP (VBZ is) (NP (NP (DT the) (VBG leading) (NN cause)) (PP (IN of) (NP (NN skin) (NN cancer))))) (. .)))