CD59 and paroxysmal nocturnal hemoglobinuria: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare bone marrow failure disorder that manifests with hemolytic anemia, thrombosis, and peripheral blood cytopenia with the absence of two glycosylphosphatidylinositol (GPI)-anchored proteins (CD55 and CD59), leading to the uncontrolled complement activation that accounts for hemolysis and other PNH manifestations [1].