PDGFA and idiopathic pulmonary fibrosis: To gain further insight into the biological function of the 13 ERSRDEGs (ADM, AGRP, BIRC3, CDA, FAM20C, IER3, MT1E, NELL2, PDGFA, RAI14, SNCA, SOCS3, and ZNF91) in IPF, we performed GO enrichment analyses (Table 2).