The study investigates the role of *PALB2*, a gene encoding a protein that interacts with BRCA2, in breast cancer susceptibility. The researchers identified monoallelic truncating *PALB2* mutations in 10 out of 923 individuals with familial breast cancer, compared to none in 1,084 controls, suggesting a 2.3-fold higher risk of breast cancer (P = 0.0025). This finding confirms *PALB2* as a breast cancer susceptibility gene and highlights the close relationship between the Fanconi anemia-DNA repair pathway and breast cancer predisposition. The study also notes that *PALB2* mutations may confer a higher relative risk of male breast cancer than female breast cancer, similar to *BRCA2* mutations. The estimated population attributable fraction of *PALB2* mutations for breast cancer is 0.23%, and the percentage of familial relative risk due to *PALB2* is 0.24%. The authors conclude that *PALB2* mutations are associated with a modestly increased risk of breast cancer, emphasizing the complex relationship between Fanconi anemia genes and breast cancer susceptibility.The study investigates the role of *PALB2*, a gene encoding a protein that interacts with BRCA2, in breast cancer susceptibility. The researchers identified monoallelic truncating *PALB2* mutations in 10 out of 923 individuals with familial breast cancer, compared to none in 1,084 controls, suggesting a 2.3-fold higher risk of breast cancer (P = 0.0025). This finding confirms *PALB2* as a breast cancer susceptibility gene and highlights the close relationship between the Fanconi anemia-DNA repair pathway and breast cancer predisposition. The study also notes that *PALB2* mutations may confer a higher relative risk of male breast cancer than female breast cancer, similar to *BRCA2* mutations. The estimated population attributable fraction of *PALB2* mutations for breast cancer is 0.23%, and the percentage of familial relative risk due to *PALB2* is 0.24%. The authors conclude that *PALB2* mutations are associated with a modestly increased risk of breast cancer, emphasizing the complex relationship between Fanconi anemia genes and breast cancer susceptibility.