TP53 and early-onset autosomal dominant Alzheimer disease: By contrast, apoptosis did not occur in Xenopus embryo hindbrains and in other model systems.78 In particular, it was described that an anti‐miR‐9 morpholino causes apoptosis in neural progenitor cells (NPCs) only in the forebrain, with mechanisms that involve the p53 pathway.79 Moreover, there is strong evidence for the function of miR‐9 in neurodegeneration, and up‐regulation of this miRNA was reported in postmortem brains of patients affected by Alzheimer's disease and reduced levels in the precocious stages of Huntington's disease.