TLR9 and acute lymphoblastic leukemia: In a recent study of NK cells obtained from patients with ALL, it was observed that the ligands of TLR3 (Poly I:C) and TLR7 (Imiquimod) increased the activation of NK cells, increasing the expression of IFN-γ, CD107a, NKG2D, and NKp44, and very importantly, the ligands of TLR8 (R848) and TLR9 (ODN 2006) increased cytotoxicity against leukemic cells (33).