However, at concentrations and doses previously shown to stimulate hormone secretion and reduce obesity-induced hyperglycaemia [24], the synthetic AhR agonist FICZ did not stimulate GLP-1 secretion from STC-1 cells (Fig. 3c), nor did it modify glucose tolerance in C57Bl6/J mice (Fig. 3d). Here, GLP1R is linked to obesity due to melanocortin 4 receptor deficiency.