TNFSF15 and rheumatoid arthritis: TNF-like ligand 1A(TL1A), a common genetic risk locus between IBD and RA, competitively binds to death receptor 3(DR3) or decoy receptor 3(DcR3), stimulates downstream signaling pathways, and affects the regulation of effector cell proliferation, activation, and apoptosis and the production of cytokines and chemokines, which eventually affect IBD and RA progression (16, 17).