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. Here, APP is linked to Alzheimer disease.