Pietri and co-workers showed that the PDK1 kinase, the central switch in the PI3K signal transduction pathway, was hyperactivated in the brains of Alzheimer Disease (AD) patients, and that inhibition of PDK1 restored the cognitive defects and ameliorated the AD-like pathology in transgenic mice models of this disease (Pietri et al., 2013). The gene discussed is PDK1; the disease is early-onset autosomal dominant Alzheimer disease.