Researchers from the Research Area on Neurological Diseases, Neuroscience, and Mental Health at the Sant Pau Research Institute, led by Dr. Juan Fortea, Director of the Memory Unit of the Neurology Service at the same hospital, have found that over 95% of individuals over 65 years old who have two copies of the APOE4 gene -APOE4 homozygotes- show biological characteristics of Alzheimer’s pathology in the brain or biomarkers of this disease in cerebrospinal fluid and PET scans.