Sabayan et al. described PDE5 inhibitors as “disease-modifyingagents” against AD and examined the molecular pathways throughwhich the inhibition of such enzymes may play a role in contrastingthe pathogenic process.9 In this context,the authors highlighted three main mechanisms that involve PDE5 and,thus, could be targeted by selective inhibitors. This evidence concerns the gene PDE5A and Alzheimer disease.