MR1 and neoplasm: Although it was shown that tumor infiltrating MAIT cells produced lower levels of IFNγ (and relatively high amounts of IL-17) compared to unaffected colon tissue and that this decrease was independent of lowered expression of MR1 on tumor cells (158, 161), the exact factors in the tumor microenvironment hampering antitumor effector cytokine secretion still remain elusive.