We wanted to evaluate the serum levels of KYN, KYNA, 3-HK and AA as well as the approximated activity of the KMO (measured by 3-HK/KYN ratio), KAT II (measured by KYNA/KYN ratio), KYNU (measured by AA/KYN ratio) and the relation of the neurotoxic TRYCAT 3-HK compared to the more neuroprotective TRYCAT KYNA (measured by 3-HK/KYNA ratio) between euthymic individuals with BD and HC. The gene discussed is KMO; the disease is Behcet disease.