In brief, immunohistochemical staining for CXCR4 has demonstrated that strong expression of CXCR4 in the cytomembranous compartment of the lung cancer tumor cells correlated with a tendency of the tumors to locally invade neighboring anatomical structures and to also form distant metastasis at sites such as the brain and pleural space. This evidence concerns the gene CXCR4 and neoplasm.