To assess the presumed relationship between PTGR1 expression and metformin efficacy, we applied lentiviral transduction to establish two PCa cell lines, i.e., DU145-PTGR1 and 22RV1-PTGR1, that can stably express PTGR1 (Fig. 4f). This evidence concerns the gene PTGR1 and posterior cortical atrophy.