+----------SUBJ:V-N---------+------COMP:V-N(in)------+    
      +----COMP:N-N(of)---+       |          +MOD_ATT:N-ADJ+    
      |           +MOD_ATT+       |          |       +MOD_A+    
      |           |       |       |          |       |     |    
 Expression of __SP__ __NODE__ occurs in __NODE__ __SP__ liver .
COMP:N-N(of) (expression,__NODE__)
MOD_ATT:N-ADJ (__NODE__,__SP__)
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,liver)
MOD_ATT:N-ADJ (liver,__NODE__)
MOD_ATT:N-ADJ (liver,__SP__)