IL2 and obesity due to melanocortin 4 receptor deficiency: iNKT cells activate various immune cells by secreting cytokines like interferon-γ (IFN-γ) and interleukin-2 (IL-2) (Nelson et al., 2021) to exert diverse biological functions, including anti-tumor, anti-viral, anti-obesity, and anti-diabetes activities (Magalhaes et al., 2015; Bonamichi and Lee, 2017; Cui et al., 2022).