NGFR and Alzheimer disease: Thus, the involvement of NGFR/p75NTR in the AD-associated brain alterations appears to be multifactorial and encompasses several ligands, including Aβ, NGF, proNGF and APP, as well as the activity of ADAM17 and γ-secretases, although the complete set of elements needed by the neurons to enter the apoptotic program in response to these interactions remains to be determined.