Whether or not ES-62 can modulate the function of such TLR-4-expressing γδ T cells during CIA is still unclear, but this is an attractive hypothesis not only because CD49+ NK cells do not express TLR-4 and are unaffected by ES-62 (Figs 2 and 3), but also because a subset of γδ T cells, defined by their ability to produce IL-22, but not IL-17, has been shown to be protective in models of colon inflammation [100] and lung fibrosis [101]. This evidence concerns the gene TLR4 and colitis.