GSR and histiocytic sarcoma: Quantification of gene expression revealed a marked increase in glutathione metabolism indicated by higher RNA expression of glutathione peroxidase 1 (GPx1), GCLC, glutathione disulfide reductase (GSR) and the glutamate/cysteine antiporter system Xc− light subunit (xCT [SLC7A11]) in TLE-HS as compared to control, while HO-1 expression remained unchanged (Fig. 2m).