+--------------SUBJ:V-N--------------+    
      +---------COMP:N-N(in)--------+      |    
      +COMP:N-N(of)+        +MOD_ATT+      |    
      |            |        |       |      |    
 Expression of IGF 1 in BALB/c3T3 cells occurs .
COMP:N-N(of) (expression,1)
COMP:N-N(in) (expression,cell)
MOD_ATT:N-N (cell,BALB/c3T3)
SUBJ:V-N (occur,expression)