In addition, dysfunction of the complement system directly underlies the etiology of several diseases, including paroxysmal nocturnal hemoglobinuria (PNH), atypical hemolytic uremic syndrome (aHUS), glomerulopathies, and CD55 deficiency with hyperactivation of complement, angiopathic thrombosis, and protein-losing enteropathy (the CHAPLE syndrome) [1]. Here, CD55 is linked to atypical hemolytic-uremic syndrome.