CXCR4 and breast cancer: In this regard, Papatheodorou et al. [50] investigated the immunoexpression of CXCR4 and CXCL12 in invasive breast carcinomas and suggested that the differential CXCR4 expression at intratumoral stroma and CXCL12 in adjacent normal mammary cells may predict clinical outcome in breast cancer patients.