Here, we find that NKG2D is neither systemically down-regulated on peripheral blood NK cells of MICAgen mice in spite of substantial amounts of sMICA plasma levels comparable with levels detected in many cancer patients (36, 37) nor on NK cells in various organs of MICAgen mice where sMICA levels may be locally concentrated (e.g., in spleen or lymph nodes). Here, KLRK1 is linked to cancer.