(S (S (S (BASENP (DT The) (NN immune) (NN system)) (VP (VBZ has) (VP (ADVP (RB apparently)) (VP (VBN evolved) (S (VP (TO to) (VP (VB be) (ADJP (RB mildly) (JJ inefficient))))))))) (SBAR (SBAR (IN so) (IN that)) (S (BASENP (PRP it)) (VP (VBZ achieves) (NP (BASENP (DT a) (NN balance)) (PP (IN between) (NP (NP (BASENP (JJ quick) (NN response)) (PP (TO to) (BASENP (NN disease)))) (CC and) (NP (BASENP (VBD decreased) (NN probability)) (PP (IN of) (NP (BASENP (JJ autoimmune) (NN disease)) (COMMA ,) (NP (BASENP (DT a) (NN condition)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (BASENP (DT the) (NN immune) (NN system)) (VP (VBZ attacks) (BASENP (JJ healthy) (NN tissue)))))))))))))))) (PERIOD .))