Recently, AMD3100 has been rigorously investigated in many clinical trials based on its capacity to suppress the CXCR4 signaling in preclinical models of multiple human cancers including lung cancer 43, osteosarcoma 44, prostate cancer 45, gastric cancer 46, hepatocellular carcinoma 47, breast cancer 48 and ovarian cancer 49. The gene discussed is CXCR4; the disease is breast cancer.