CYP1B1 and obesity due to melanocortin 4 receptor deficiency: Studies have shown that Kynurenine caused obesity by activating AHR (Moyer et al., 2016), while obesity and hepatic steatosis were prevented by inhibiting AhR, the AhR antagonist naphthoflavone (aNF) prevented and reversed obesity in high-fat diet mice by inhibiting AhR and related genes in its network, such as CYP1B1 and stearoyl-CoA desaturase-1 (SCD1) (Moyer et al., 2017; Xu et al., 2015).