CXCR4 and neoplasm: This includes attraction of CXCR4 expressing immune cells during premalignant chronic inflammation and malignant transformation 3, formation of a tumor-supporting niche by recruitment of bone marrow derived progenitor cells, fibroblasts and pro-tumorigenic immune cell subsets (MSDCs, Treg, M2 macrophages) 4, homing of CXCR4 overexpressing tumor cells, auto- and paracrine stimulation of tumor growth, vasculogenesis, invasion and distant metastasis as well as therapy resistance and immune evasion 5, 6.