NK cells that reconstitute at an early stage in vivo from CD34⁺ HSCs display distinct phenotypic characteristics intrinsic to their maturation. CD56^bright (left panels) and CD56^dim (right panels) NK-cell subsets of healthy blood donors (n = 31; ) and of patients at day 30 after haploidentical (n = 22; ■), HLA-matched (related, n = 2, and unrelated, n = 4; □), and autologous (n = 5; ▧) HSCT were analyzed separately for expression of several NK-cell subset-specific receptors. From top to bottom: (A) inhibitory receptors (KIRs and NKG2A), (B) activating receptors (NKp30, NKp44, NKp46, NKG2D), (C) well-characterized markers of NK-cell functions: CD16 for antibody-dependent-cellular cytotoxicity (ADCC); CD25 and CD132, respectively, the α and γ chain of the IL-2 receptor; CD62L for lymph node homing; and CD117 (c-kit), which is expressed by hematopoietic progenitors, as well as by differentiating and mature CD56^bright NK cells.^34,35  Shown are the average percentages of expression and SE. Both donors and patients with a “null” KIR3DL1 phenotype were not considered in the analysis of KIR3DL1 expression. Asterisks indicate significant posthoc comparisons of patients at day 30 after HSCT from haploidentical donors after correction for multiple comparisons (false discovery rate; see “Statistical analysis” for details).