CARS1 and neoplasm: Moreover, additional genetic modifications for introduction of antigen-specific receptors, such as chimeric antigen receptors (CARs) (Uherek et al., 2002) or T-cell receptors (TCRs) (Mensali et al., 2019; Parlar et al., 2019), or overexpression of activating receptors (Sayitoglu et al., 2020), are being explored in an attempt to further enhance the anti-tumor efficacy of NK cell therapies.