NPTX2 and early-onset autosomal dominant Alzheimer disease: Now, in eLife, Paul Worley from the Johns Hopkins University School of Medicine and co-workers – including Mei-Fang Xiao and Desheng Xu as joint first authors – report that the loss of a protein called NPTX2 disrupts interneuron-mediated circuit activity in Alzheimer’s disease (Xiao et al., 2017).