+----------------SUBJ:V-N----------------+                    
      +-----------COMP:N-N(of)-----------+     |                    
      |           +-----MOD_ATT:N-ADJ----+     +--COMP:V-N(in)-+    
      |           |       +--MOD_ATT:N-N-+     |       +MOD_ATT+    
      |           |       |      +MOD_ATT+     |       |   +MOD+    
      |           |       |      |       |     |       |   |   |    
 Expression of __SP__ Add 1 [__NODE__] mRNA occurs in 3T3 L1 cells .
COMP:N-N(of) (expression,mRNA)
MOD_ATT:N-ADJ (mRNA,__SP__)
MOD_ATT:N-N (mRNA,1)
MOD_ATT:N-N (mRNA,[__NODE__])
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,cell)
MOD_ATT:N-ADJ (cell,3T3)
MOD_ATT:N-N (cell,L1)