KEGG pathway enrichment analysis revealed that differentially expressed proteins were mainly involved in complement and coagulation cascade, COVID-19, PPAR signalling pathway, mineral absorption, cholesterol metabolism, ferroptosis, staphylococcus aureus infection, bile secretion, systemic lupus erythematosus, folate biosynthesis, and proximal tubule bicarbonate reclamation (Figure 4(D)). This evidence concerns the gene PPARA and systemic lupus erythematosus.