NOS2 and idiopathic pulmonary fibrosis: Figure 1 illustrates the heat map and Venn diagram of DEGs. Then, DEGs were further classified using the FERDB online tool into three categories of ferroptosis drivers (CA9, EPAS1, CDO1, CDKN2A, ALOX15), ferroptosis suppressors (TP63, CAV1, PROM2, JUN), and ferroptosis markers (NOS2, HNF4A, RGS4, SLC2A1, GDF15, SLC2A12, NGB, DRD5, GPX2, HBA1). The edgeR results showed that there were 1854 differentially expressed genes between IPF lung tissue and normal lung tissue (Supplementary Table S1).