The importance of CXCR4 (specifically the SDF-1-CXCR4 axis) in B-ALL homing and migration has been well documented.8,14,18 Our CXCR4 expression data is novel and provides direct evidence for the effect of anaesthetics on migration, demonstrating that general anaesthetics reduce CXCR4-dependent chemotaxis in NALM-6 and Reh cells. The gene discussed is CXCR4; the disease is precursor B-cell acute lymphoblastic leukemia.