CCL18 and esophageal squamous cell carcinoma: This analysis found the expression of 7 differentially upregulated ligands including T cell marker genes CCL5 and GZMA, monocyte marker genes CCL3, CCL3L1 and CCL4, macrophage marker genes CCL18, GZMA and DC marker gene GZMB, which may impact the infiltration and distribution of the cells in ESCC TME (Fig. 4A left panel).