+------------------SUBJ:V-N------------------+    
     +------------COMP:N-N(of)------------+       |    
     |                      +-MOD_ATT:N-N-+       |    
     +COMP:N-N(of+          |     +MOD_ATT+       |    
     |           |          |     |       |       |    
 Relation of __NODE__ and cell surface protein occurs .
COMP:N-N(of) (relation,__NODE__)
COMP:N-N(of) (relation,protein)
MOD_ATT:N-N (protein,cell)
MOD_ATT:N-N (protein,surface)
SUBJ:V-N (occur,relation)