KLRD1 and cancer: Although CTA-specific T cells are less likely to express high level of activation-induced IRs,37–39 some of them can demonstrate upregulation of germline-like IR expression, such as CD94/NKG2a with compromised antitumor activity.40 Exploring how to improve antitumor activities of CTA-specific CTLs could provide profound and broader clinical benefits to cancer patients.