GSR and cystic fibrosis: GR, crucial for maintaining the pool of reduced GSH, has shown varied alterations depending on the cell type or tissue examined; studies have reported GR activity to be unvaried in erythrocytes of CF children (Carmagnol et al., 1983), while intracellular GR activity was significantly higher in lung tissue from Cftr-KO mice (Velsor et al., 2001), and conversely, significantly decreased in CF bronchial epithelial cells compared to WT controls (de Bari et al., 2018).