This observation was confirmed nine years later by Hilpert et al., who discovered that 70% of AML blasts were positive for at least one NKG2D ligand (with 15% of patients having leukemic cells expressing even four or five different NKG2D ligands), and in addition, 100% of patients with AML in this study had detectable serum levels of NKG2D ligands with MICA being the one most often detected in the sera (97). Here, KLRK1 is linked to acute myeloid leukemia.