CCL3 contributes to tumor progression and poor prognosis in ESCC patients by binding CCR5 on ESCC cells, activating PI3K/Akt and MEK/ERK pathways, upregulating MMP-2 and VEGF-A expression, and promoting cell migration, invasion, and angiogenesis (Fig. 8). This evidence concerns the gene MMP2 and esophageal squamous cell carcinoma.