In contrast, the up-regulated genes in SCGB3A2high club cells in IPF were related to immune response, antigen processing and presentation, interferon-gamma signaling pathway, cellular protein metabolic process, and T cell co-stimulation (S4B Fig in S1 File), suggesting that the SCGB3A2high club cells of IPF patients were highly associated with immune cell maturation. Here, IFNG is linked to idiopathic pulmonary fibrosis.