Thus, in our study we evaluated the IDO and IL-6 expression of biopsy specimens and IL-6 level of serum collected prior to neoadjuvant chemotherapy based on clinical and pathological response to chemotherapy, to explore the association between IDO, IL-6 expression and clinicopathological features, response to neoadjuvant chemotherapy and prognosis of breast cancer patients. Here, IL6 is linked to breast cancer.