A mechanistic link between IL-6 and DCCs reactivation is still missing, but elevated levels of IL-6 have been correlated with increased rates of tumor relapse in breast cancer and head and neck cancer (49, 50) while inhibition of IL-6/STAT3 signaling reduced cancer recurrence in preclinical models of breast, head and neck and hepatocellular carcinoma (51–54). Here, IL6 is linked to head and neck cancer.