NKG2C⁺CD57⁺FcεR1γ⁺ NK cells from recipients of TCD HCT with CMV reactivation exhibit greater effector response compared with NKG2C⁺CD57⁺FcεR1γ⁻ NK cells. Comparing the effector function of (A) NKG2C⁺FcεR1γ⁺ vs NKG2C⁺FcεR1γ⁻ of total NK cells, and (B) CD57⁺FcεR1γ⁺ vs CD57⁺FcεR1γ⁻ of NKG2C⁺2A⁻ NK cells derived from recipients of TCD HCT with CMV reactivation (n = 6). The gates in the dot plots represent NK cell populations that were analyzed for effector function. Percentages of CD107a (left) and IFN-γ (right) of indicated NK cell subpopulations are depicted. Two-way ANOVA with multiple comparisons were used for statistical analysis, with ∗P ≤ .05; ∗∗P ≤ .01; ∗∗∗P ≤ .001; ∗∗∗∗P ≤ .0001.