NOX4 and Marfan syndrome: Oxidative stress has been linked to syndromic and nonsyndromic familial aortic diseases28,56; moreover, in MFS mice redox stress is associated with NOX4 (NADPH oxidase 4), which is upregulated in the aortas of MFS patients and whose deficiency protects MFS mice from elastic-fiber fragmentation and aortic dilation28.