IL6 and breast cancer: IL-19 is produced by monocytes, and activates these cells in an autocrine and paracrine fashion to release the cytokines IL-6, TNF-α, and numerous ROS. Monocyte IL-19 production is downregulated by IFN-γ (Commins et al., 2008).IL-19 has an autocrine effect in breast cancer cells; it promotes cell proliferation and migration (Chen et al., 2013).