NGFR and Alzheimer disease: Some key examples are Notch, a key regulator of Wnt signaling that promotes proliferation during neurogenesis but is also repressed during neural differentiation [13], and p75NTR, a neurotrophin receptor and cell cycle regulator which has been proposed to be involved in AD via multiple modes of action including neuronal growth regulation, differentiation and cellular survival, and cellular senescence [163, 164].