C8， a component of the complement system consists of three polypeptides C8A， C8B and C8G and takes part in the formation of Membrane Attack Complex （MAC）. Patients with C8 deficiency are exposed to several bacteria infections. C8G， a member of the lipocalin family and calycin superfamily， is a secreted protein that can bind retinol. C8G is created in the liver， monocytes and fibroblast and has a role in clearing pathogens from an infected host.
