In the TME, serine activates mTOR to inhibit FOXP3 expression and further hinder Tregs immunosuppressive capacity, but the transformation of serine to glutathione through glutamate cysteine ligase (Gclc) contributed to preserve Tregs immunosuppressive function, and Gclc ablation showed autoimmunity and enhanced anti-tumor responses [145]. The gene discussed is GCLC; the disease is neoplasm.