IL6 and cancer: Cytokines produced by cancer tissue [11, 12] and the expression of interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12, and IL-19, monocyte-chemoattractant-protein (MCP-) 1, and macrophage-inflammatory-protein- (MIP-) 1β are upregulated in breast cancer [7, 13, 17, 19].