+--------------SUBJ:V-N--------------+--COMP:V-N(in)-+    
      +----COMP:N-N(of)----+               |       +MOD_ATT+    
      |            +MOD_ATT+          +-NEG+       |   +MOD+    
      |            |       |          |    |       |   |   |    
 Expression of __NODE__ protein does not occur in 3T3 L1 cells .
COMP:N-N(of) (expression,protein)
MOD_ATT:N-ADJ (protein,__NODE__)
SUBJ:V-N (occur,expression)
NEG (occur,not)
COMP:V-N(in) (occur,cell)
MOD_ATT:N-ADJ (cell,3T3)
MOD_ATT:N-N (cell,L1)