NK cell repertoire diversity increases during NK cell reconstitution after CBT. (A) NK cell repertoire diversity at multiple points after CBT in patients with CMV reactivation during the first 100 days posttransplant (red) compared with results for patients without CMV reactivation (blue). Days 14-30 CMV reactive (n = 8 samples), CMV negative (n = 5 samples); days 31-60 CMV reactive (n = 17 samples), CMV negative (n = 11 samples); days 61-100 CMV reactive (n = 20 samples), CMV negative (n = 5 samples). PB samples from CMV-reactive patients were collected after CMV reactivation. Mann-Whitney U test was used to compare values among the subjects. Boxes represent median with minimum to maximum range. Statistical significance is indicated as *P ≤ .05; **P ≤ .01. (B) Diversity of KIR⁺ NK cells (red) vs KIR⁻ NK cells (blue) in PB samples collected from CBT recipients with or without CMV reactivation within 100 days post-CBT. Boxes represent median with minimum to maximum range. ***P ≤ .001. (C) The manually pregated CD56⁺KIR⁺ and CD56⁺KIR⁻ NK cell populations from a representative CBT recipient with CMV reactivation in the first 100 days after transplant were exported and down-sampled to an equal cell number of 2000 for each sample. Individual t-SNE maps show the expression of 29 different NK cell markers. Color scales indicate signal intensity, ranging from low (blue) to high (red) after arcsine transformation. Bar plots under each t-SNE map depict the frequencies of NK cells expressing each marker in the KIR⁺ and KIR⁻ NK cell populations. *P ≤ .05; **P ≤ .01; ***P ≤ .001; ****P ≤ .0001. Bars represent median with interquartile range.