IL6 and breast cancer: Meta-analytic evidence substantiates this effect; for instance, a recent systematic review and meta-analysis focusing on overweight and obese women with breast cancer demonstrated that exercise significantly reduced levels of C-reactive protein (CRP) (MD: -0.52, 95% CI: -0.94 to -0.11) and interleukin-6 (IL-6) (MD: -0.87, 95% CI: -1.62 to -0.11), although the reduction in tumor necrosis factor-α (TNF-α) was not statistically significant (47).