CXCR4 and ovarian cancer: In this context, various cancer cells demonstrate a significant expression of functional CXCR4 on the cell surface including A549 lung cancer [51], SK-OV-3 ovarian cancer [52], brain tumors like CCF-STTG1 astrocytoma [53], HT-29 colon adenocarcinoma [54], and much more tumor entities.