KLRK1 and cancer: Numerous studies have documented the expression of NKG2D ligands in different cancer types to be important in NK cell-mediated tumor eradication (Bugide et al, 2018a; Cho et al, 2014; Friese et al, 2003; Salih et al, 2003; Vetter et al, 2002; Watson et al, 2006).