+------SUBJ:V-N------+----COMP:V-N(in)----+    
      +COMP:N-N(of)+       |           +MOD_ATT:+    
      |            |       |           |        |    
 Expression of __NODE__ occurs in endothelial cells .
COMP:N-N(of) (expression,__NODE__)
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,cell)
MOD_ATT:N-ADJ (cell,endothelial)