The area density of phosphorylated tau (p‐tau), amyloid beta (Aβ), α‐synuclein, and phosphorylated TDP‐43 protein deposits together with pyramidal cell density in each hippocampal subregion, including CA1‐4, prosubiculum (ProS), and subiculum was assessed in 166 cases encompassing various neurodegenerative diseases. This evidence concerns the gene MAPT and neurodegenerative disease.