PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 17388633-6 2007 The reactivity of indolequinones 2 and 3 is further decreased due to their stronger electron-donating substituents at C-4. Indolequinones 18-32 complement C4A (Rodgers blood group) Homo sapiens 118-121