IL6 and breast cancer: VEGF, plasminogen activator inhibitor-1 (PAI-1), tumor necrosis factor (TNF-α), and interleukin (IL-6) secretion were significantly higher when the 4T1 cells were cultured in 50% RAW-CM, suggesting that macrophage-related mediators in the conditioned media promoted carcinogenic and inflammatory cytokine production by the breast cancer cells (p < 0.05).