GADD45A and Parkinson disease: Our study firstly demonstrated that post-treatment with erinacine A could reduce MPTP-induced neurotoxicity via activation of the PAK1, AKT, LIMK2, MEK, and Cofilin survival pathways, as well as reduction of the IRE1α, TRAF2, ASK1, GADD45, and p21 cell death pathways in N2a neuron cells and in an MPTP model of Parkinson’s disease (Figure 9).