Gradual decline in GPI-anchored protein–negative granulocytes in a PNH patient after nonmyeloablative HCT. Granulocytes were analyzed in patient no. 5 before and multiple time points after transplantation using CD15 (PE) as a non-GPI–anchored protein and CD66b (FITC) and CD16 (PECy5) as GPI-anchored proteins. Following the white blood cell nadir, a population of GPI-negative granulocytes was detected beginning at neutrophil recovery.