Even minor disturbances of ATF4 function contribute to serious pathologies, such as the neurodegenerative Parkinson’s, Alzheimer’s, and Huntington’s diseases; prion diseases, and various types of retinal degeneration.14 Furthermore, persistent overactivation of ATF4, which does not induce apoptosis, is linked to many cancers because of the continuous expression of adaptive genes that sustain the stress response.15 This evidence concerns the gene ATF4 and Parkinson disease.