CD24 and paroxysmal nocturnal hemoglobinuria: Flow cytometry of the paroxysmal nocturnal hemoglobinuria (PNH) clones revealed a 2.9% glycophosphatidyl inositol (GPI)-deficient granulocyte and a 2.9% CD24-deficient granulocyte expansion, which suggest that either the AA transformed into myelodysplastic syndrome (MDS) or the original underlying disease was MDS.