Figure 2.

CXCL5 promotes the recruitment of vascular endothelial cells for angiogenesis and helps form the tumor-promoting microenvironment. Tumor cells secret CXCL5 for interaction with its receptor CXCR2, which subsequently activates NF-κB and AKT signaling transduction in endothelial cells. CXCL5 facilitates the recruitment and activation of inflammatory myeloid-derived suppressor cells (MDSCs), eventually leading to persistent inflammation and immunosuppression, thereby stimulating tumor progression. MDSCs, myeloid-derived suppressor cells; EC, endothelial cell; STAT3, signal transducer and activator of transcription 3; NF-κB, nuclear factor‐κappa B; VEGF-A, vascular endothelial growth factor-A; FOXD1, Forkhead Box D1.