IL6 and cancer: One of these isoforms (TGF-β1) is a potent inducer of metastasis.18 Previous studies have shown that elevated levels of inflammatory mediators such as TNF-α and IL-6 are involved in the progression and relapse of breast and head and neck cancers, while inhibition of IL- 6 signaling has been reported to reduce cancer recurrence in preclinical models of breast, head and neck and hepatocellular carcinoma.1,18