KLRK1 and idiopathic aplastic anemia: Notably, the percentage of MAIT cells expressing the activator receptor NKG2D was significantly higher in the bone marrow specimens of the aplastic anemia patients than in MAIT cells from the patients with other bone marrow syndromes [median, IQR 26.5% (22.44–50.5) vs. 17.9% (6.25–21), p = 0.01] (Figure 1E).