Glutathione and Xanthine Metabolic Changes in Tamoxifen Resistant Breast Cancer Cell Lines are Mediated by Down Regulation of GSS and XDH and Correlated to Poor Prognosis Excessive glutathione intake contributes to chemotherapy resistance in breast cancer: a propensity score matching analysis World Journal of Surgical Oncology Springer Nature Link Catabolism of extracellular glutathione supplies cysteine to support tumours Nature Chemotherapy induces breast cancer stem cell enrichment through repression of glutathione S transferase Mu ScienceDirect