FADS2 and obesity due to melanocortin 4 receptor deficiency: Obesity results in STING activation and production of cytokines, which leads to insulin tolerance and metabolic disorders.[43] STING regulates polyunsaturated fatty acid (PUFA) metabolism by inhibiting the rate‐limiting enzyme activity of fatty acid desaturase 2 (FADS2).[11] Furthermore, STING also acts as a proliferative inhibitor in T lymphocytes of the adaptive immune system.[44] Therefore, increasing evidence has shown that STING has other functions in addition to immunity.