By interacting with IL-6 receptor (IL-6R), IL-6 activates STAT3 by upregulating the expression of cyclin D1, D2, and B1, and c-Myc and downregulating the expression of the cyclin-dependent kinase (CDK) inhibitor p21, which collectively accelerates the entry of tumor cells into cell cycles [165]. This evidence concerns the gene STAT3 and neoplasm.