( ( ( Heterophile antibodies ) ( are ( so-named ( because ( they ( can ( react ( with ( antigens ( from ( unrelated species ) ) ) ) ) ) ) ) ) ) ) ( , ( it ( ( is ( one ( of ( ( the ( many products ) ) ( of ( EBV infection ) ) ) ) ) ) . ) ) ) )
(ROOT (S (S (NP (JJ Heterophile) (NNS antibodies)) (VP (VBP are) (ADJP (JJ so-named) (SBAR (IN because) (S (NP (PRP they)) (VP (MD can) (VP (VB react) (PP (IN with) (NP (NP (NNS antigens)) (PP (IN from) (NP (JJ unrelated) (NNS species)))))))))))) (, ,) (NP (PRP it)) (VP (VBZ is) (NP (NP (CD one)) (PP (IN of) (NP (NP (DT the) (JJ many) (NNS products)) (PP (IN of) (NP (NNP EBV) (NN infection))))))) (. .)))
Heterophile antibodies are so-named because they can react with antigens from unrelated species, it is one of the many products of EBV infection.
(ROOT (S (NP (DT An) (NN antibody)) (VP (MD can) (VP (VB match) (NP (NP (CD one) (NNS types)) (PP (IN of) (NP (NNS antigens)))))) (. .)))