Moreover, Adams et al. [40] revealed that the expression of kynurenine aminotransferase I (KAT I), one of the key enzymes in KYNA synthesis, was significantly decreased after stimulation with interferon-gamma (IFN-γ) in human glioma cells, which significantly lowered the KYNA/KYN neuroprotective ratio. The gene discussed is IFNG; the disease is glioma.