In patients carrying either the APOE4 allele or having a first-degree family history of Alzheimer’s disease, years of education and cortical thickness were positively correlated in the parahippocampal cortex (Pearson’s r=0.45, p=0.045), and across all medial temporal subregions combined (r=0.48, p=0.031). The gene discussed is APOE; the disease is Alzheimer disease.