GPX3 and cystic fibrosis: Given the common pancreatic insufficiency in CF leading to selenium malabsorption, reduced GPx activity is plausible (Winklhofer-Roob et al., 1998; Baker, 2008; Zheng and Mostamand, 2023), particularly for plasma GPx (GPx3), which is closely linked to selenium availability (Ottaviano et al., 2009).