( It ( ( involves ( ( the ( white ( blood cells ) ) ) ( known ( as leukocytes ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ involves) (NP (NP (DT the) (JJ white) (NN blood) (NNS cells)) (VP (VBN known) (PP (IN as) (NP (NNS leukocytes)))))) (. .)))
It involves the white blood cells known as leukocytes.
(ROOT (S (NP (JJ Leukocytes) (NN blood) (NNS cells)) (VP (VBP are) (ADJP (JJ white))) (. .)))