It is likely that the reduction of expression of CXCR4 is related to the enhancement of chemosensitivity given some have reported the CXCR4 antagonist the chemoresistancein vitro in ALL cells.19 In addition, X Hu et al has reported that CXCR4 may mediated autophagy signalling via SIRT1 and enhanced chemoresistance in AML cells.20 It could be reasonability speculated that at least propofol enhanced cytotoxicity of Ara-C via cytotoxic autophagy mediated by CXCR4 related mechanisms. The gene discussed is CXCR4; the disease is acute lymphoblastic leukemia.