Like CD1d−/− mice, Jα18−/− mice had identical body weight to WT mice on high fat diet (Figure 11A) After verifying by FACS that both strains were, indeed, deficient in iNKTs, we were surprised to find that high fat fed Jα18−/− mice did not develop increased hepatic steatosis (Figure 11B) Moreover, Jα18−/− mice, unlike CD1d−/− mice, did not show any trend towards glucose intolerance on a glucose tolerance test (Figure 11C), nor did they exhibit abnormally elevated plasma insulin during the glucose tolerance test (Figure 11D). The gene discussed is CD1D; the disease is Hepatic steatosis.