Activating receptor expression on NK cells in NK-DLI vs circulating in vivo and killing capacity of aNK-DLI. (A) Flow cytometry was used to phenotype the aNK-DLI product as well as the circulating lymphocyte subsets shown at the time of protocol enrollment (baseline), following EPOCH-F chemotherapy (pretreatment [PreTx]), and at sequential time points following HSCT. Asterisks represent time points wherein the phenotype measured differed from the product; *P < .05, **P < .005. Red, subjects who developed GVHD; black, subjects who did not develop GVHD. (B) Pooled analysis of aNK-DLI products tested for killing of TC71 Ewing sarcoma cell line without blocking fusion proteins (n = 9, designated “none”) and with the designated fusion proteins (n = 7, for each blocking antibody) to block the activating receptors noted. Asterisks denote where killing is different from that observed without fusion protein blockade (P < .05).