LTBR and colitis: We note that LIGHT deficiency increased colitis even in DSS-treated Rag−/− mice and therefore LIGHT was acting not in T cells but in the innate immune system.6 Colonic neutrophils expressed high amounts of both LIGHT and LTβR mRNA,6 suggesting a possible autocrine signaling loop mediated by LIGHT, although the cell type providing the required LIGHT remains to be identified.