( ( ( Both types ) ( of ( the virus ) ) ) ( ( ( studied ( cause disease ) ) ( in humans ) ) . ) )
(ROOT (S (NP (NP (DT Both) (NNS types)) (PP (IN of) (NP (DT the) (NN virus)))) (VP (VBD studied) (NP (NN cause) (NN disease)) (PP (IN in) (NP (NNS humans)))) (. .)))
Both types of the virus studied cause disease in humans.
(ROOT (S (NP (NP (JJ Protist) (NNS diseases)) (PP (IN in) (NP (NNS humans)))) (VP (VBP are) (VP (VBN caused) (PP (IN by) (NP (NN protozoa))))) (. .)))