+--------SUBJ:V-N--------+    
      +---COMP:N-N(in)--+      |    
      +COMP:N-N(+       |      |    
      |         |       |      |    
 Expression of IGF in liver occurs .
COMP:N-N(of) (expression,IGF)
COMP:N-N(in) (expression,liver)
SUBJ:V-N (occur,expression)