C5 and atypical hemolytic-uremic syndrome: Treatment of paroxysmal noctural hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS) and myasthenia gravis has been performed for a long time by inhibiting complement factor C5 (using the anti-C5 antibodies eculizumab and ravulizimab) with excellent results (85–87).