( ( ( The symptoms ) ( of ( the ( common cold ) ) ) ) ( ( are ( believed ( to ( be ( mostly ( related ( to ( ( the ( immune response ) ) ( to ( the virus ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NNS symptoms)) (PP (IN of) (NP (DT the) (JJ common) (NN cold)))) (VP (VBP are) (VP (VBN believed) (S (VP (TO to) (VP (VB be) (ADJP (RB mostly) (VBN related) (PP (TO to) (NP (NP (DT the) (JJ immune) (NN response)) (PP (TO to) (NP (DT the) (NN virus))))))))))) (. .)))
The symptoms of the common cold are believed to be mostly related to the immune response to the virus.
(ROOT (S (NP (NP (NNS Symptoms)) (PP (IN of) (NP (JJ viral) (NNS diseases)))) (VP (VBP result) (PP (IN from) (NP (DT a) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (JJ immune) (NN response))) (PP (TO to) (NP (DT a) (NN virus)))) (. .)))