+-----COMP:V-N(in)-----+    
      +------SUBJ:V-N------+         +MOD_ATT:N-AD+    
      +COMP:N-N(of)+       |         |      +MOD_A+    
      |            |       |         |      |     |    
 Expression of __NODE__ occurs in smooth muscle cells .
COMP:N-N(of) (expression,__NODE__)
SUBJ:V-N (occur,expression)
COMP:V-N(in) (occur,cell)
MOD_ATT:N-ADJ (cell,smooth)
MOD_ATT:N-N (cell,muscle)