High CCL20 expression levels were positively correlated to tumor stage and grade, as well as the occurrence of pleural metastases in human triple-negative breast cancer cell lines.25,48 Moreover, previous study showed that CCL20 could promote BCSC self-renewal through the activation of nuclear factor kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) activity.28 Nevertheless, there is no evidence of a causative or functional link between TME regulated by CCL20 and breast cancer progression, particularly in BCSCs. Here, CCL20 is linked to breast cancer.