+----------SUBJ:V-N---------+-----COMP:V-N(in)-----+    
      +----COMP:N-N(of)---+       |         +MOD_ATT:N-AD+    
      |           +MOD_ATT+       |         |     +MOD_AT+    
      |           |       |       |         |     |      |    
 Expression of __SP__ __NODE__ occurs in __SP__ brain tissue .
COMP:N-N(of) (expression,__NODE__)
MOD_ATT:N-ADJ (__NODE__,__SP__)
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,toilet)
MOD_ATT:N-ADJ (toilet,__SP__)
MOD_ATT:N-N (toilet,brain)