FOXO3 and cardiac hypertrophy: Mice lacking FoxO1 are embryonically lethal by E10.5 due to impaired vasculogenesis, and mice lacking FoxO3 are viable but develop cardiac hypertrophy as adults (Hosaka et al., 2004; Ni et al., 2006), indicating the different functions of FoxO1 and FoxO3 in the cardiovascular system.