FMO5 and Hyperoxaluria: Hyperoxaluria-mediated oxidative stress not only increases the enzymatic activity of oxidases such as NADPH oxidase (gp91phox) and xanthine oxidase but also leads to reduced antioxidant defenses, including the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione reductase (GR) [29,34].