IL6 and breast cancer: Xenograft-bearing mice fed a high-fat diet (HFD) exhibit increased expression of IL-6 and TNF-α to sustain the local chronic inflammatory microenvironment and favor M1 macrophages, which together with nicotine increase macrophage infiltration and anti-inflammatory cytokines, such as IL-10, IL-13, and IL-4, promote BC growth and invasive behaviors67.