CXCR2 and esophageal squamous cell carcinoma: The authors [166] also observed that CXCL8 was upregulated in peripheral blood monocytes (PBMo)-derived macrophages stimulated with conditioned media of TE-series ESCC cell lines (TAM-like PBMo-derived macrophages), which facilitated the migration and invasion of ESCC cells by inducing the phosphorylation of the AKT and ERK1/2 signaling pathway through activation of CXCR1 / CXCR2 receptors.