PARK7 and Parkinson disease: Double transgenic mice for DJ-1 deficiency and α-Syn expression (expressing pathogenic Ala53Thr human a-Syn) called M83-DJ-1 null mice, revealed that onset of disease and pathological changes were not different when compared with single transgenic M83 mice line and concluded that α-Syn and DJ-1 mutation may lead to PD via independent mechanisms13.