LRRK2 and Alzheimer disease: Since pS935-LRRK2 not only phosphorylates pS129-αSyn [24], but may also be involved in the regulation of OS [25,26] and apoptosis [27,28,29], among other cellular functions [30,31], in typical PD cholinergic neurons, we speculate that the neuropathological hallmark of PD α-Syn may coexist with AD and that the LRRK2 protein may function in both diseases.