Our analysis indicated that AQP9, PROK2, LCN2, and NAMPT were positively linked to the IL-17/IL-17-associated signaling pathway (rheumatoid arthritis, systemic lupus erythematosus, and type 1 diabetes mellitus), immune-related disorders (allograft rejection and graft-versus-host disease) or infection (leishmaniasis and malaria)8. Here, LCN2 is linked to rheumatoid arthritis.