OPRD1 and Alzheimer disease: Activation of DOR with its specific agonist UFP-512 substantially decreased BACE1 expression and its activity in a highly differentiated rat PC-12 cell line with imitated AD injury, whereas DOR antagonism with naltrindole reversed the UFP-512 effects while causing an enhancement of BACE1 expression and activity along with Aβ42 production under physiological conditions (Antonino et al., 2022).