SPG11 and hereditary spastic paraplegia: Pérez-Brangulí and colleagues, using 2D and 3D models, differentiating neural progenitor cells (NPCs), neurospheres, and cerebral organoids, from patient iPSCs carrying SPG11 mutations, showed an increased level of asymmetric division in SPG11 NPCs in the germinal zone of cortical ventricles at the expense of symmetric division, shedding new light on the neurodevelopmental mechanism underlying this type of HSP.