In PAD, upregulation of DDAH at a local level to reduce ADMA levels within the ischaemic muscle may be of benefit in a number of ways: it may improve microvascular function and local tissue perfusion; it may improve the results of therapeutic angiogenesis by reducing the antiangiogenic environment; or it may improve muscle contractile and metabolic function and perhaps reduce tissue damage. Here, DDAH1 is linked to peripheral arterial disease.