+----------------SUBJ:V-N----------------+                                                  
      +-------COMP:N-N(of)-------+             +-------COMP:V-N(in)-------+                       
      |           +-MOD_ATT:N-ADJ+             |         +--MOD_ATT:N-ADJ-+                       
      |           |       +MOD_AT+        +-NEG+         |        +MOD_ATT+------APPOS------+     
      |           |       |      |        |    |         |        |       |                 |     
 Expression of __SP__ __NODE__ mRNA does not occur in __SP__ peripheral blood lymphocyte ( PBL ) .
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,blood)
MOD_ATT:N-ADJ (blood,__SP__)
MOD_ATT:N-ADJ (blood,peripheral)
APPOS (blood,PBL)