+-------------SUBJ:V-N------------+--COMP:V-N(in)--+    
      +----COMP:N-N(of)---+             |        +MOD_ATT+    
      |            +MOD_AT+        +-NEG+        |   +MOD+    
      |            |      |        |    |        |   |   |    
 Expression of __NODE__ mRNA does not occur in WEHI 3B cells .
COMP:N-N(of) (expression,mRNA)
MOD_ATT:N-ADJ (mRNA,__NODE__)
SUBJ:V-N (occur,expression)
NEG (occur,not)
COMP:V-N(in) (occur,cell)
MOD_ATT:N-N (cell,WEHI)
MOD_ATT:N-ADJ (cell,3B)