APP and Alzheimer disease: Rack1 is a multifaceted scaffolding protein highly expressed in neuronal cells, and plays important roles under both physiological and pathological conditions.[16, 17, 18, 19] Most studies of Rack1 in AD have focused on neurons, where it has been reported to regulate APP processing and modulate Aβ‐induced toxicity.[18] However, the role of Rack1 in microglia in the CNS remains largely unknown.