Additionally, the transcriptional activity of STAT3 is a prerequisite for the regulation of tumor invasion and metastasis.35, 36, 37 Studies on the relationship between IL-17 and interferon gamma (IFN-γ) have found that the expression level of IL-17 is positively correlated with the degree of activation of the STAT3 signaling transduction pathway.38 As some similar structural domains exist in both of IL-17 and IL-6, we deduced that the mechanism underlying IL-17-mediated STAT3 activation may be similar to the mechanism underlying IL-6-induced STAT3 activation. This evidence concerns the gene IL6 and neoplasm.