+--------------SUBJ:V-N-------------+                       
      +-------COMP:N-N(of)-------+        |                       
      |           +-MOD_ATT:N-ADJ+        |                       
      |           |       +MOD_AT+        |                       
      |           |       |      |        |                       
 Expression of __SP__ Rld 1 [__NODE__] occurs in pituitary gland .
COMP:N-N(of) (expression,[__NODE__])
MOD_ATT:N-ADJ ([__NODE__],__SP__)
MOD_ATT:N-N ([__NODE__],1)
SUBJ:V-N (occur,expression)