In agreement with our findings in humans and MPTP-induced parkinsonism, cultured naïve SN4741 DA neurons exposed to the DA neuron selective neurotoxin MPP+, a dynamic producer of ROS, caused an early and progressive down-regulation of Skp1, concomitantly with Aldh1 and Hsc-70 proteins. The gene discussed is ALDH1A1; the disease is Parkinson disease.