We found that the amount of TrkA bound to APP was significantly lower in all three AD samples, as shown in Fig. 5D. Analysis of the TrkA‐positive co‐immunoprecipitated band relative to the input showed lower binding in AD (*P < 0.05; 56.4 ± 12, %CTR), as compared to both CTR and OND (108 + 15, %CTR), while no difference was found between CTR and OND (P = 0.6) hippocampal samples. This evidence concerns the gene NTRK1 and Alzheimer disease.