Dysregulation of ER-α expression appears to be common for neurotoxins, since studies have shown that the PD neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) decreased ER-α levels in mice (D'Astous et al., 2004) and paraquat, another PD-modelling neurotoxin, also reduced ER-α levels in PC12 cells (Gelinas et al., 2004). The gene discussed is ESR1; the disease is Parkinson disease.