The cumulative risk of death from BC during the first 5 years after diagnosis was 20.3% (95%CI 16.9–24.2) for cases with mean PAK1 CN <4, 23.1% (95% CI 11.1–44.3) for cases with CN ≥4<6, and 18.2% (95% CI 7.2–41.5) for cases with CN ≥6 (Fig 3, Table 4). This evidence concerns the gene PAK1 and breast cancer.