+---------SUBJ:V-N--------+                            
      +----COMP:N-N(of)---+     |                            
      |            +MOD_AT+     +COMP:V-N(+                  
      |            |      |     |         |                  
 Expression of __NODE__ mRNA occurs in __SP__ adrenal gland .
COMP:N-N(of) (expression,mRNA)
MOD_ATT:N-ADJ (mRNA,__NODE__)
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,__SP__)