Since AKT/GSK3β signal transduction impairment is believed to be associated with dopaminergic neuronal dysfunction in PD (Morissette et al., 2010; Chen et al., 2017), we also explored whether the protective function of OCN on SN dopaminergic neurons is mediated via AKT/GSK3β signaling. This evidence concerns the gene AKT1 and Parkinson disease.