PNP and Alzheimer disease: Regarding purine metabolism, ENTPD2, NME3, PNP, and PRUNE RNAs are deregulated in the frontal cortex in AD (91), whereas ADA, AK1, ENTPD1, NME1, NME3, NME4, NME6, PNP, and PRUNE are upregulated in rpDLB with changes less marked in DLB.