1. IL-4 is involved in regulation of different types of otitis media. 2. IL-4 is one of the cytokines responsible for an allergic type of inflammation owing its ability to induce local immunoglobulin class switching to IgE (Fig 6) . 3. IL-4 can support local humoral inflammatory responses by increasing production and secretion of immunoglobulins in activated B cells (Figs 4 and 6 ). 4. IL-4 can also support cell-mediated chronic inflammation in the middle ear by promoting generation of multinucleated giant cells (Figs 5 and 6 ), although it is necessary to note that giant cells in OME have not been investigated. 5. IL-4 can also participate in the regulation of mucin metabolism and the mucociliary transport system in middle ear inflammation.