In the mouse model of ectopic tracheal transplantation, IL-17A is involved in the pathogenesis of obliterative bronchiolitis by regulating M1 macrophage polarization (44), but whether IL-17A mediates periodontal tissues destruction by promoting M1 macrophage polarization and secreting inflammatory factors remains to be studied. This evidence concerns the gene IL17A and bronchiolitis obliterans syndrome.