TNF and otitis media with effusion: Afterwards, the mice were maintained for another 3 weeks (4 weeks after LPS) and examined again for the inflammatory cell recruitment and macrophage polarization in OME, the levels of major pro-inflammatory cytokines IL-1β, IL-6, TNFα, and IFNɣ in OME, and the levels of ROS, MDA, GSH, and SOD in the middle ear mucosae tissue.