KLRK1 and cancer: Shedding of sNKG2DL is a phenomenon well characterized in cancer patients in whom high plasma levels of sNKG2DL released by transformed cells can not only decrease cell-surface ligand expression, but also inactivate/downmodulate NKG2D on circulating lymphocytes and allow efficient evasion of NKG2D-mediated anti-tumor responses [67].