C5, C6, C7, C8 and C9 are the factors present in common terminal pathway. The classic activation pathway, mannose-binding lectin activation pathway and alternative activation pathway converge on the final common terminal pathway. The cleavage of C3 by each pathway (classic activation pathway, mannose-binding lectin activation pathway and alternative activation pathway) causes activation of C5, C6, C7, C8 and C9 in the terminal pathway, resulting in the formation of membrane attack complex (MAC) that gets attached to the target cells or bacteria and lyses them. Ref: Harrisons Principles of Internal Medicine, 16th Edition, Page 1913 & 1916.