+------------SUBJ:V-N------------+                               
      +-------COMP:N-N(of)-------+     +------COMP:V-N(in)------+      
      |           +-MOD_ATT:N-ADJ+     |         +-MOD_ATT:N-ADJ+      
      |           |       +MOD_AT+     |         |      +MOD_ATT+      
      |           |       |      |     |         |      |       |      
 Expression of __SP__ __NODE__ mRNA occurs in normal __SP__ epidermis .
COMP:N-N(of) (expression,mRNA)
MOD_ATT:N-ADJ (mRNA,__SP__)
MOD_ATT:N-ADJ (mRNA,__NODE__)
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,epidermis)
MOD_ATT:N-ADJ (epidermis,normal)
MOD_ATT:N-ADJ (epidermis,__SP__)