IL6 and breast cancer: Moreover, IL-6 and leptin secreted by adipocytes lead to subsequent activation of pathways such as JAK/STAT3 and PI3K/AKT, and downstream expression of pro-inflammatory cytokines including Interleukin 6 (IL-6), Interleukin 1 beta (IL-1β), and Tumor necrosis factor alpha (TNF-α) in breast cancer cells [43,44].