KLRF1 and chronic myelogenous leukemia, BCR-ABL1 positive: The comparison of NK cells from old TKI-treated CML patients with those from old healthy individuals shows a lower expression of NK receptors NKp44, NKp80, CD69, and HLA-DR in both CD56bright and CD56dim NK cells and also a reduced expression of NKp30, NKG2D, and NKG2A in CD56bright NK cells (Figure 6C).