KIR3DL1 and cancer: To alleviate such inhibition on NK cells and thus to enhance their cytotoxicity against a patient's cancer cells, elaborately selecting an NK cell donor for that particular patient to obtain a KIR-HLA mismatch in an anti-cancer direction is critical (Benson and Caligiuri, 2014, Leung, 2014, Murphy et al., 2012, Thielens et al., 2012).