In mice with small intestinal inflammation or OVA-induced lung inflammation, NKT cells, activated and memory CD4+ T cells, or eosinophils are likely to be a main source of the Th2 cytokines that are induced by the TL1A-DR3 signaling pathway [10, 24, 26, 27], suggesting that TL1A-DR3 signaling in these cells might be a therapeutic target in asthma and ulcerative colitis. This evidence concerns the gene TNFSF15 and asthma.