Scans of coronal histological sections of cerebral hemisphere from participants in the AN1792 trial immunolabelled to demonstrate amyloid-β (appearing black). The cases are grouped according to the extent of positive histological evidence of plaque removal on examination of all brain regions (Method 1). (A) Placebo with neuropathologically confirmed Alzheimer’s disease demonstrating a continuous band of plaques throughout the cerebral neocortex (Case 15). (B) Alzheimer’s subjects with nearly complete plaque removal (Cases 7, 8, 16, 20 and 21). (C) Alzheimer’s subjects with intermediate plaque removal (Cases 1, 2, 6 and 9). (D) Alzheimer’s subjects with limited plaque removal (Cases 4, 10, 11, 17 and 22). (E) Alzheimer’s subjects with no evidence of plaque removal (Cases 3 and 19). (F) Non-Alzheimer’s subjects (Cases 5, 12, 13, 14 and 18). Amyloid-β plaque density was scored throughout the neocortex of each hemisphere section using a CERAD-adapted method (Method 2) with the results colour-coded for illustrative purposes as: frequent plaques = red, moderate = yellow, sparse = green, none = blue, expressed as % of each category.