PIR and Alzheimer disease: Results of piRNA target prediction showed that these piRNAs mainly focused on 5 most significant AD-associated pathway targets, which were enriched with 4 genes (CYCS, LIN7C, KPNA6, and RAB11A) that were regulated by 4 piRNAs (piR-38240, piR-34393, piR-40666, and piR-51810).