In addition to the new findings with Traj18−/− (1-1 L) mice, we observed similar weight gain curves for Traj18−/− (1-1 L) and Cd1d−/− mice on HFD, which would be consistent with a limited role of type 2 NKT cells in the development of obesity. The gene discussed is CD1D; the disease is obesity due to melanocortin 4 receptor deficiency.