+--------------SUBJ:V-N--------------+                    
      +----COMP:N-N(of)----+               +--COMP:V-N(in)-+    
      |            +MOD_ATT+          +-NEG+         +MOD_A+    
      |            |       |          |    |         |     |    
 Expression of __NODE__ protein does not occur in 256Mel 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,256Mel)