( ( ( A ( fatal disease ) ) that ) ( ( ( ( attacks and ) destroys ) ( ( the ( body 's ) ) ( immune system ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (JJ fatal) (NN disease)) (NP (DT that))) (VP (VBZ attacks) (CC and) (VBZ destroys) (NP (NP (DT the) (NN body) (POS 's)) (JJ immune) (NN system))) (. .)))
A fatal disease that attacks and destroys the body's immune system.
(ROOT (S (NP (DT The) (JJ immune) (NN system)) (ADVP (RB typically)) (VP (VP (VBZ recognizes)) (, ,) (VP (VBZ attacks)) (, ,) (CC and) (VP (VBZ destroys) (NP (NP (JJ foreign) (NNS cells) (CC or) (NNS substances)) (SBAR (WHNP (WDT that)) (S (VP (MD may) (VP (VB cause) (NP (NN disease))))))))) (. .)))
The immune system typically recognizes, attacks, and destroys foreign cells or substances that may cause disease.