Transcription of the CAT gene is directly stimulated by FOXO3 (Rangarajan et al. 2015, Song et al. 2016) and FOXO6 (Kim et al. 2014), and is positively regulated by FOXO1 (Awad et al. 2014, Liao et al. 2016, Guo et al. 2016), although direct regulation by FOXO1 has not been demonstrated. CAT encodes the enzyme catalase, which converts hydrogen peroxide to water and oxygen, thus protecting cells from the oxidative stress.