Abstract Background Natural killer (NK) cells are an important resource of the innate immune system directly involved in the spontaneous recognition and lysis of virus-infected and tumor cells. An exquisite balance of inhibitory and activating receptors tightly controls the NK cell activity. At present. one of the best-characterized activating receptors is NKG2D. https://www.roneverhart.com/Cleglaw-s-Tooth-West-Ladder/