In addition, the expression level of IL-8 also correlates with tumor recurrence (Fig. 1e, P < 0.01), cervical lymphatic metastasis (Fig. 1f, P = 0.045), and advanced stage (Fig. 1g, P = 0.035), but does not correlate with age, smoking, drinking, or gender (Fig. 1h–k, respectively). Here, CXCL8 is linked to metastasis.