CXCR4 and ovarian epithelial tumor: Another study showed that the positive rate of CXCR4 in malignant epithelial tumors was significantly higher than that in normal ovarian epithelial tumors, benign epithelial tumors and borderline epithelial tumors (CXCR4:80% vs. 0, 15%, 40%) (Guo et al., 2011).