In ocular degenerative diseases, the elevation of ATF4 as well as the activation of the UPR have been described in different retinal cell types, reviewed in [14], however, the involvement of ATF4 in the pathology of diabetes [15], oxygen-induced retinopathy [16, 17] and retinitis pigmentosa [3, 5, 18] remains unclear. This evidence concerns the gene ATF4 and retinitis pigmentosa.