CXCR4 and acute myeloid leukemia: Moreover, a co-delivery system of doxorubicin (Dox) and E5 with DSPE-mPEG2000 was constructed (Zhang et al., 2022), which can effectively bind to the CXCR4-expressing AML cells, downregulate the signaling proteins mediated by CXCR4/CXCL12 axis and increase the cellular uptake of Dox.