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