GDF2 and Alzheimer disease: Using a AD mouse model (APP.PS1), which exhibit cholinergic defects, high accumulation of amyloid plaques, and cognitive impairments, Burke et al. found that intracerebroventricular infusion of BMP-9 (4 ng/h) for 7 days can reduce Aβ42-positive plaques in the cortex and hippocampus [106].