DCX and Alzheimer disease: Figure 2 in the paper by Tobin et al. [3] shows that DCX+ cells are located not only around the subgranular zone, but also in the middle and outer parts of the GCL, where mature GCs are typically located, in elderly humans and AD patients, raising the possibility that at least some of the DCX+ cells are GCs that underwent dematuration, rather than being newly generated.