CAT and cystic fibrosis: Our results revealed that the activity levels of superoxide dismutase (1.96 ± 0.08) and catalase (0.60 ± 0.28) were significantly lower in CF children compared to non-CF children (2.03 ± 0.10, p = 0.027, and 1.12 ± 0.09, p < 0.001, respectively).