on the other hand, have undergone some trials in the clinical arena. The efficacy and safety of EW-A-401, an engineered zinc-finger transcription factor, as a pharmacologic agent for treating claudication, a cardiovascular ailment, has been investigated in clinical trials. The protein consists of an engineered plasmid DNA that prompts the patient to produce an engineered transcription factor, the target of which is the vascular endothelial growth factor-A (VEGF-A) gene, which positively influences blood vessel development. Although not yet approved by the U.S. Food and Drug Administration (FDA), two Phase I clinical studies have been completed which identify this zinc-finger protein as a promising and safe potential therapeutic agent for treatment of peripheral arterial disease in humans. See also Artificial transcription factor Antisense therapy Gene therapy RNA interference References Medical genetics Applied genetics