This so-called oxygen paradox [6] mainly acts on three sources of OFR generation: Breakdown products like xanthine or hypoxanthine, that unnaturally accumulate during anoxic catabolism of high energy phosphates [7] can be metabolized at very high rates by xanthine oxidase (XOD), a radical generating isoform of the enzyme xanthine dehydrogenase (XDH) induced during ischemia [8]. This evidence concerns the gene XDH and ischemia.