Phenotypic characteristics of NK cells after allogeneic SCT. (A) FACS profile of CD56^highCD16^–/low and CD56^lowCD16^high subpopulations of NK cells in a patient after SCT compared with the healthy donor. (B) Percentage of CD56^highCD16^–/low and CD56^lowCD16^high NK cell subpopulations and expression of NK cell markers NKp46, CD161, HLA-DR, and CD69 in patients after SCT and healthy donors (N) is shown (mean ± SEM). Time after transplantation is indicated. *P < .05, **P < .005 compared with healthy donors.