In this study, we first determined the changes of CgA levels and how they correlate with tau pathology, in the cortices of AD, corticobasal degeneration (CBD), and hTau mice, where the human Tau (1N4R) protein with the P301S mutation is expressed under the PRNP (prion protein gene) promoter 24.Subsequently, we explored the effects of CgA ablation in hTau mice with regard to neuropathology, cognitive function and transcriptomics. This evidence concerns the gene PRNP and Alzheimer disease.