Natural killer group 2 member D (NKG2D), which is mainly expressed on NK cells and CD8+ T cells (Dhar and Wu, 2018), is an important activating receptor for NK cells that mediates cytotoxic effects on tumor cell clearance by recognizing NKG2D ligands on the surface of tumor cells (Alexandra et al., 2019). The gene discussed is KLRK1; the disease is neoplasm.