This is coherent with genome-wide association studies (GWAS) that show an association between AhR expression (and the regulation of KYN-biosynthesizing enzymes, together with the levels of KYN) and the severity of major depressive disorders [181], or by a recent study on the damages induced by the KYN/AhR following experimental stroke [182]. The gene discussed is AHR; the disease is major depressive disorder.