NTRK1 and Alzheimer disease: With respect to other neurotrophic factors, the gene and protein expression levels of the nerve growth factor receptor p75 and TrkA in Neuro2a cells are increased by ginsenoside Re and Rd, which suggest that the NGF-TrkA signaling pathway mediates the ginsenoside-induced neuroprotective effects against AD progression (Kim et al., 2014).