Agents and compounds which can be used to modulate the activity of the complement system, novel biological targets associated with such modulation, and pharmaceutical compositions, medicaments and methods of treatment for use in preventing, ameliorating or treating diseases that are characterised by inappropriate complement activity. These diseases include age-related macular degeneration (AMD), meningitis, renal disease, autoimmune disease and inflammation. Therapeutic antibodies and screening assays for identifying agents useful in treating these diseases are also provided.
