Recently, Krüppel-like factor (KLF) 5 directly transcriptionally regulated by FoxO1 was shown to cause oxidative stress via induction of NADPH oxidase (NOX) 4 expression, a major source of cytosolic ROS levels [62] in cardiomyocytes of STZ-induced T1D mice [51]. The gene discussed is FOXO1; the disease is type 1 diabetes mellitus.