( ( ( one 's ) antibody ) ( ( is ( another ( 's antigen ) ) ) . ) )
(ROOT (S (NP (NP (CD one) (POS 's)) (NN antibody)) (VP (VBZ is) (NP (NP (DT another)) (POS 's) (NN antigen))) (. .)))
one's antibody is another's antigen.
(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)))))) (. .)))