+--------------SUBJ:V-N-------------+                       
      +----COMP:N-N(of)---+               +---COMP:V-N(in)---+    
      |           +MOD_ATT+          +-NEG+          +MOD_ATT+    
      |           |       |          |    |          |       |    
 Expression of __SP__ __NODE__ does not occur in skeletal muscle .
COMP:N-N(of) (expression,__NODE__)
MOD_ATT:N-ADJ (__NODE__,__SP__)
SUBJ:V-N (occur,expression)
NEG (occur,not)
COMP:V-N(in) (occur,muscle)
MOD_ATT:N-ADJ (muscle,skeletal)