A BRCA2 mutation has been reported to be associated with an increased risk of breast, gastric, pancreatic, and prostatic cancer in men, and female carriers appear to be at higher risk of gastric cancer than male carriers.13–15) Prostatic cancer screening is recommended for a man with a BRCA2 pathogenic variant.16–18) The present patient’s daughter had breast cancer. The gene discussed is BRCA2; the disease is gastric cancer.