APP and familial Alzheimer disease: We included fibroblasts from two individuals with a familial Alzheimer's disease (FAD) mutation in the amyloid β precursor protein (APP), two non-demented control (NDC) individuals, three individuals with sporadic Alzheimer's disease (SAD), and one individual with hippocampal sclerosis (Table 1) to ensure that our methods would be applicable for analysis of cell lines regardless of disease status.