During the first 10 years after diagnosis, the cumulative risk of death from BC was 30.1% (95% CI 26.1–34.5) for cases with mean PAK1 CN <4, 26.9% (95% CI 13.9–48.3) for cases with CN ≥4<6, and 40.9% (95% CI 23.8–63.9) for cases with CN ≥6. The gene discussed is PAK1; the disease is breast cancer.