IPF outcomes are worsened by treatment with low dose Prednisone, Azathioprine (Idiopathic Pulmonary Fibrosis Clinical Research Network et al., 2012), and unaffected by treatment with biologics targeting interferon gamma (King et al., 2009) or TNFα (Raghu et al., 2008). This evidence concerns the gene IFNG and pulmonary fibrosis.