+-------COMP:V_PASS-N(in)------+        
     +MOD_ATT+SUBJ:V_PASS+             +---MOD_ATT:N-N--+        
     |       |           |             |                |        
 __NODE__ protein is involved in proliferation of keratinocytes .
MOD_ATT:N-ADJ (protein,__NODE__)
SUBJ:V_PASS-N (involve,protein)
COMP:V_PASS-N(in) (involve,keratinocytes)
MOD_ATT:N-N (keratinocytes,proliferation)