In the immune system, recent studies suggested prominent role of RORα in regulating T cell and ILC2 development (15, 16) and immune cell functions, including T regulatory cells in allergic skin inflammation (17), Th17 driven inflammatory disorders (18, 19), survival of CD4+ T cells in colitis (20) and lung infection (21), ant-tumor immunity of liver-resident natural killer cells/ILC1s (22), macrophage activation in LPS-induced septic shock (23) and diet-induced obesity (24), and ILC3 driven fibrosis (25). This evidence concerns the gene RORA and colitis.