NTRK2 and Alzheimer disease: This is an indication that the decreased BDNF and/or BDNF/TrkB signaling in AD could possibly be, at least in part, responsible for the increase in the STEP level, suggesting that, in AD, Aβ induces alterations in BDNF/TrkB signaling to alter synaptic morphology possibly via increasing activation and protein level of STEP.