Taken together with proNGF functions in its triggering p75NTR-sortilin complex and initiating apoptosis signal, this study overall indicated that proNGF might appeal a new possible mechanism underlying aberrant microglial activation-mediated neurotoxicity in neuroinflammation state, also suggesting that proNGF may be a potential therapeutic target for the neurodegenerative diseases such as AD, PD and ALS [4,7]. Here, NGFR is linked to Alzheimer disease.