CXCL8 and breast carcinoma: IL-8 expression is inversely correlated with ER status, but positively correlated with estradiol; moreover, breast cancer patients with high levels of IL-8 during the early stages are in relation to shorter relapse-free survival (RFS), whereas patients with low IL-8 levels are associated with ER− PR− and Her-2− Her-2+ phenotypes35.