CTH and cancer: This approach was well tolerated and more effective in depleting GSH in the brain of healthy rats compared to PAG alone.46 In other cancer models, the enzyme cyst(e)inase was found to efficiently degrade circulating cysteine, thereby increasing oxidative damage and decreasing tumor load.47 In conclusion, we here identified a specific dependency of IDH1m astrocytomas on CSE to maintain antioxidant homeostasis suggesting pharmacological inhibition of CSE as a potential strategy that warrants further investigation.