CD4 and neoplasm: Next, to investigate the role of CCL20 in remodeling the tumor microenvironment, we analyzed the immune-related gene expression in tumor tissues with high and low CCL20 expression, and found that the expression of Foxp3, CD4, and TGF-β, one of the mainly functional molecules secreted from Tregs [20], in tumor tissues with high CCL20 expression was significantly higher than that in tumor tissues with low CCL20 expression (Fig. 3b).