PRKN and Parkinson disease: The role of ATF4 has been further explored by Imai et al. and Bouman et al., who proposed that the PD-like progression in mice could involve the binding of activated ATF4 to the E3 ligase parkin promoter (Imai et al., 2000, 2001) and the mediation of parkin expression in response to ER and mitochondrial stress (Bouman et al., 2011).