This is clinically relevant because, as noted above, the type I NKT cell number in peripheral blood has been reported to be suppressed in cancer patients (80, 83, 131) compared with healthy donors, and their IFN-γ-producing function is frequently diminished in patients (81, 132–135), making the balance in cancer patients more like that in Jα18−/− mice. Here, IFNG is linked to cancer.