Another study that analyzed the expression of TLR4 in middle ear effusions and tissues after injection of NTHi—an important cause of middle ear infection—into the tympanic bulla of C3H/HeN mice, confirmed that TLR4 causes accumulation of polymorphonuclear cells in the early stage of inflammation and activates their functions to eliminate NTHi infections in the middle ear cavity [37]. The gene discussed is TLR4; the disease is infectious otitis media.