In another example, mice deficient in the IFN-γR exhibit more severe disease following infection with murine gamma-herpesvirus-68 (MHV-68), including interstitial and intra-alveolar fibrosis that is reminiscent of idiopathic pulmonary fibrosis (IPF) in human beings. Here, IFNGR1 is linked to idiopathic pulmonary fibrosis.