Whilst the failure to find a correlation of AT-8 phospho-tau in the AD cases may be due to a ceiling effect of pathology or indeed the correlation of variables across only two Braak stages, it is nevertheless striking that in non-AD control cases, AT-8 phospho-tau increases within the frontal cortex in line with the inter-regional spatial progression of NFTs. The gene discussed is MAPT; the disease is Alzheimer disease.