High circulating levels of IL-6 have been reported in patients with different types of cancers such as breast [31], colorectal [32], ovarian [33], renal [34], non-small-cell lung cancer (NSCLC) [35], and head and neck [36], and circulating IL-6 levels are reported to be increased in patients with recurrent tumors [37]. This evidence concerns the gene IL6 and cancer.