In addition, to determine whether circulating IL-8 levels reflect the tumor microenvironment, especially the immunological microenvironment, we used immunohistochemical staining to analyze the expression of IL-8 as well as the infiltration of immune-inhibitory cells such as Foxp3-positeve regulatory T cells (Tregs) and CD163-positive M2 macrophages, which may be adverse prognostic markers [8], [9], [13]. Here, CXCL8 is linked to neoplasm.