Cancer treatment has been transformed, at its root, by a transformational change in how it is classified. These days, which organ a tumor arises in is often less important than its molecular drivers, which can be sensitive either to specific targeted treatments, or increase the chance that a tumor will respond to immunotherapy. Those successes have not escaped the notice of researchers in other areas of biomedicine, and diseases including heart failure, asthma and polycystic ovarian syndrome are being looked at with an eye to subdividing them in ways that brings diagnostics into the molecular era. Nowhere do those changes have greater potential than in disorders of the brain – in part because there is nowhere much to go but up as far as classifying neurological diseases goes.

LONDON – New human brain organoids that precisely model the three hallmarks of Alzheimer’s disease – amyloid plaque-like lesions, progressive neuronal death and abnormal accumulations of tau – are now ready to be developed for use in high-throughput drug screening.