Adenoviruses, which are common respiratory tract viruses with more than 50 serotypes, have been proven to cause latent infections, especially in lymphoid tissues.20, –22 Early region 1A, which is a viral gene product of adenoviruses, has been reported to promote the production of profibrotic mediators, such as connective tissue growth factor and transforming growth factor-β mRNA on the bronchial epithelium.23 In the case of a latent adenovirus infection, the continuous release of these profibrotic mediators may trigger fibrosis development. This evidence concerns the gene CCN2 and disease arising from reactivation of latent virus.