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