As we find decreased NDP expression in the hippocampus of both late-onset AD brains and NDAD brains (Fig 6), suggesting a role for NDP in adult neurogenesis, we therefore tested recombinant norrin on primary murine adult subventricular zone (SVZ) progenitors as well as human iPSC-derived NPCs for effects of on proliferation. Here, NDP is linked to Alzheimer disease.