Wendy Nelson holds her cat Piper, in Foxborough, Massachusetts, U.S., March 21, 2023. Nelson’s mother died from Alzheimer’s disease, her father suffers from it, and genetic tests through 23andMe shows that Wendy carries two APOE4 gene variants, and her three daughters each carry one APOE4 gene variant, indicating an increased risk of Alzheimer’s disease. REUTERS/Brian Snyder