While DJ-1 knockdown by siRNA or DJ-1 deficiency heightened their sensitivity to oxidative stress in a variety of model systems, including cell lines, embryonic stem cells, fruit flies and rodents [13], [14], [15], [16], [17], [18], overexpression of wild-type DJ-1 but not PD associated mutants protects cells against oxidative insult or mitochondrial toxins in these models [11], [14], [19], [20]. Here, PARK7 is linked to Parkinson disease.