Cancer cells may evade NK cell-mediated cytotoxicity by dysregulating MHC-I expression28, increasing the expression of dysfunction markers (including PD-L1, TGF-β, etc.)11, disturbing natural cytotoxicity receptor (NCR)-mediated activation29, or repressing the expression of NKG2D ligands (NKG2DLs, including ULBPs and MICA/B)12,19,30,31. The gene discussed is KLRK1; the disease is cancer.