NFE2L2 and Parkinson disease: Cysteamine (CSEA) and its oxidized form cystamine (CSA) counteract oxidative stress and inflammation and also upregulate protective signaling through brain-derived neurotrophic factor (BDNF) in a mouse Parkinson’s disease (PD) model and Nrf2 transcription in the CNS (Borrell-Pagès et al., 2006; Calkins et al., 2010; Paul and Snyder, 2019).