SGK1 and Parkinson disease: The level of SGK1 is relatively higher in the midbrain than in other brain regions, and upregulation of SGK1 coincides with the onset of DA neuron death in a model of PD (Iwata et al, 2004; Stichel et al, 2005), collectively suggesting that SGK1 plays pathogenic roles in PD and other neurodegenerative disorders.