The following drugs against C5a or C5aR1 are either currently available, have been withdrawn, or are in preclinical trials: 1) Eculizumab (Soliris®) is a humanized antibody against C5, approved for treatment of rare disorders (paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome). Here, C5AR1 is linked to atypical hemolytic-uremic syndrome.