TNF and idiopathic interstitial pneumonia: TNFa was found significantly associated with a decreased risk of IPF by IVW models (OR, 0.999; 95% CI, 0.998-1.000, P = 0.002), whereas the opposite result was observed in the MR Egger method (OR, 1.000; 95% CI, 0.998–1.002, P = 0.927) (Fig. 4).