CXCL12 and acute myeloid leukemia: We previously reported that a novel peptide, E5 (GGRSFFLLRRIQGCRFRNTVDD), interferes with the CXCR4/CXCL12 axis by significantly inhibiting stromal-induced activation in acute myelocytic leukemia cell lines in vitro,21 and enhancing the efficacy of chemotherapeutics in the acute myelocytic leukemia mouse model.22