KEGG pathway analysis of DEIRGs in LUAD identified 13 significant pathways, including cytokine–cytokine receptor interaction, JAK-STAT signaling pathway, hematopoietic cell lineage, neuroactive ligand–receptor interaction, renin–angiotensin system, viral protein interaction with cytokine and cytokine receptor, C-type lectin receptor signaling pathway, allograft rejection, type I diabetes mellitus, intestinal immune network for IgA production, autoimmune thyroid disease, and tight junction (Figure 5A and Supplementary Table S9). This evidence concerns the gene REN and type 1 diabetes mellitus.