+----------------SUBJ:V-N----------------+                                         
      +-------COMP:N-N(of)-------+             +-----------COMP:V-N(in)-----------+      
      |           +-MOD_ATT:N-ADJ+             |              +---MOD_ATT:N-ADJ---+      
      |           |       +MOD_AT+        +-NEG+              |           +MOD_ATT+      
      |           |       |      |        |    |              |           |       |      
 Expression of __SP__ __NODE__ mRNA does not occur in undifferentiated __SP__ monocytes .
COMP:N-N(of) (expression,mRNA)
MOD_ATT:N-ADJ (mRNA,__SP__)
MOD_ATT:N-ADJ (mRNA,__NODE__)
SUBJ:V-N (occur,expression)
NEG (occur,not)
COMP:V-N(in) (occur,monocyte)
MOD_ATT:N-ADJ (monocyte,undifferentiated)
MOD_ATT:N-ADJ (monocyte,__SP__)