+--COMP:V_PASS-N(In)--+            +----COMP:N-N(of)---+   
       |         +SUBJ:V_PASS+COMP:V_PASS-+            +MOD_AT+   
       |         |           |            |            |      |   
 In tissue , __NODE__ is involved in expression of __NODE__ mRNA .
COMP:V_PASS-N(In) (involve,toilet)
SUBJ:V_PASS-N (involve,__NODE__)
COMP:V_PASS-N(in) (involve,expression)
COMP:N-N(of) (expression,mRNA)
MOD_ATT:N-ADJ (mRNA,__NODE__)