CXCL8 and cancer: Interleukin 8 (CXCL8/IL8) is secreted by tumor cells and acts with CXCR1/2 in tumor microenvironment to regulate the proliferation and self-renewal of cancer stem cells (CSCs), which plays an important role in tumor progression and metastasis by regulating inflammatory factors [31].Some inflammatory markers such as CXCL8, interleukin-6, tumor necrotic factor, and C-reactive protein (CRP) were recently identified as prognostic markers in oral cavity cancer [17].