+----------SUBJ:V-N---------+                                   
      +----COMP:N-N(of)---+       +--COMP:V-N(in)--+                  
      |           +MOD_ATT+       |         +MOD_AT+COMP:N-N(of+      
      |           |       |       |         |      |           |      
 Expression of __SP__ __NODE__ occurs in __SP__ islets of Langerhans .
COMP:N-N(of) (expression,__NODE__)
MOD_ATT:N-ADJ (__NODE__,__SP__)
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,islet)
MOD_ATT:N-ADJ (islet,__SP__)
COMP:N-N(of) (islet,Langerhans)