No other studies have reported low expression of NKG2D in HESN nor elite controllers; however, Muntasell et al. demonstrated that viral exposure in a model of CMV infection resulted in a decreased NKG2D expression, which selectively limited the ability of NK cells to kill target cells that express high levels of NKG2D ligands while preserving the expression of other NK activation molecules and the NK cytotoxic potential [44]. Here, KLRK1 is linked to cytomegalovirus infection.