Natural killer (NK) cells are lymphocytes that either directlyattack or activate the adaptive immune system in responseto detection of malignant or virally infected cells. Theyhave a well-known safety profile and the ability to act asallogeneic immune modulators, which makes NK cells anattractive option for off-the-shelf immunotherapeutics [1].In the clinical setting, strategies are being developed toimprove NK cell function, persistence, and trafficking totumor sites [2]. These include inserting chimeric antigenreceptors (CARs) and using complementary antibodies toenhance the identification and destruction of tumor cells,as well as ex vivo expansion and activation techniques.