Differentiation of NK cells in humans following HSCT. (A) Frequency of NK cells out of total lymphocytes in donor (time-point zero) and HSCT-recipient (longitudinally sampled at weeks 4, 8, 16, 34, and 52 post-HSCT) pairs. (B) Frequency of CD56^bright and CD56^dim cells out of total NK cells for donor and HSCT-recipient pairs. (C) Frequency of NKG2A expressing CD56^dim NK cells out of total NK cells for donor and HSCT-recipient pairs. (D) Frequency of CD57 expressing CD56^dim NK cells out of total NK cells for donor and HSCT-recipient pairs. (E) Frequency of CD57 expressing KIR⁻ and KIR⁺ CD56^dim NK cells out of total NK cells for donor and HSCT-recipient pairs. (F) Frequency of Ki67 expressing CD57^+/−CD56^dim NK cells for donor and HSCT-recipient pairs. For A-F; n = 5; mean ± SEM.