CXCR4 and acute myeloid leukemia: Previous studies have shown that the interaction between the bone marrow microenvironment and AML cells is important for chemoresistance and disease relapse, and that the CXC chemokine receptor 4 (CXCR4) and CXC chemokine ligand 12 play important roles in regulating the interaction between the bone marrow microenvironment and leukemic cells [6,7,8,9,10].