Farrell and colleagues confirmed that while the genetics of PART overlap to some degree with sporadic late‐onset AD, individuals with PART have a higher APOE ε2 allele frequency, which distinguishes PART from AD both neuropathologically and genetically, and a lower frequency of the APOE ε4 allele, as demonstrated in previous studies in independent cohorts. The gene discussed is APOE; the disease is Alzheimer disease.