Binding to CXCR4 with the β-hairpin mimicry, balixafortide inhibited the CXCL12-induced activation of downstream MAPK-ERK/PI3K-AKT pathways in the lymphoma and AML cell lines and blocked the CXCL12-dependent chemotaxis in breast cancer and leukemia cell lines (35, 95, 97). The gene discussed is CXCL12; the disease is breast cancer.