Given that the increased expression of ARG1 and the subsequent depletion of l-arginine are a potent mechanism used by immunosuppressive cells to inhibit inflammation (see below), it is likely that the activation of immunosuppressive network, such as what occurs during aging [8], causes a deficiency of NO synthesis and thus elicits vascular disorders (Figs. 2 and 3). The gene discussed is ARG1; the disease is vascular disorder.