Complement C9

**Definition:** A 63-kDa serum glycoprotein encoded by gene C9. Monomeric C9 (mC9) binds the C5b-8 complex to form C5b-9 which catalyzes the polymerization of C9 forming C5b-p9 (MEMBRANE ATTACK COMPLEX) and transmembrane channels leading to lysis of the target cell. Patients with C9 deficiency suffer from recurrent bacterial infections.

**Tree numbers:** - D12.776.124.486.274.850

**Synonyms:** - C9 Complement - Complement 9 - Complement Component 9