Patients with AML exhibit a low NK-cell frequency and significantly lower NK cell activity in the peripheral blood, as well as lower expression of NCR, NKp46, NKp44, NKp30, and C-type lectin receptors, NKG2C and NKG2D (Szczepanski et al., 2011). The gene discussed is KLRK1; the disease is acute myeloid leukemia.