HSPB1 and Alzheimer disease: To better understand the relationship between HSPB1 and the astrocyte response to amyloid pathology in AD brain, we measured protein levels of HSPB1 within 50 μm from the edge of Aβ plaques, a distance that has been previously used to define plaque-associated local toxicity, including the accumulation of dystrophic neurites, activated microglia, and reactive astrocytes (23), which we referred to as “proximal” to plaques, in relation to equivalent areas beyond 50 μm from plaques, which were considered “distal” areas (Fig. 1B).