CXCR2 and nasopharyngeal carcinoma: Moreover, a significant positive correlation was detected between CXCR2 expression in stromal cells and CXCL8 expression in tumors in 99 NPC specimens (P < 0.05) but not between CXCR2 expression in tumor cells and CXCL8 expression in tumors (P > 0.05), which might indicate that tumor could regulate the behaviors of stromal cells in the tumor microenvironment via CXCL8-CXCR2 signaling (Figure 1B).