BRCA1 and cancer: Through a comprehensive NGS analysis of the high-penetrance BRCA1/2 genes and 23 additional moderate- and low-penetrance genes in a large cohort of 333 unselected OC women from northern Poland, we estimated the overall ethnicity-specific pathogenic variants’ frequency in these genes at ~26%, including ~21% of the BRCA1/2 mutation-positive individuals and ~5% of cases with pathogenic alterations in the other cancer-related genes.