IL6 and breast cancer: Acute increases in PM2.5 and sulfate were associated with increased C-reactive protein, which was also true for NOx in case of interleukin-6 and for BC, sulfate, and O3 in case of tumor necrosis factor receptor 2. Conversely, BC, sulfate, and NOx were negatively associated with fibrinogen, and sulfate was negatively associated with tumor necrosis factor α.