CAT and vitiligo: In addition, patients with vitiligo have down-regulated enzymes, such as catalase (CAT) (Agrawal et al., 2014) and dysregulated superoxide dismutase (SOD) (Koca et al., 2004; Khan et al., 2009; Ozel Turkcu et al., 2014), and abnormal non-enzyme defense to oxidants like the total antioxidant capacity (TAC) (Hayran et al., 2021).