By using flow cytometry in this patient we were able to identify the advent of a novel population of RBC (freshly produced from the patient’s own bone marrow) not coated with C3d during ECZ treatment indicating a halt in the alternative complement pathway overdrive—of notice ECZs therapeutic target (C5) is downstream of the C3 convertase, so even though C5b-C9 generation is inhibited by ECZ and hereby intravascular hemolysis C3b/d depositing is still possible and may lead to non-neglectable extravascular hemolysis as seen in patients with PNH (34, 35). This evidence concerns the gene C5 and paroxysmal nocturnal hemoglobinuria.