As mentioned above, family history of ovarian cancer in first degree relatives increases the risk for epithelial ovarian cancer; studies on these families have led to the identification of moderate-to-high penetrance genes favoring ovarian cancer development: BRCA1, BRCA2 and the DNA mismatch repair gene RAD51C. It was estimated that germline BRCA1 and BRCA2 mutations contribute to the development of 10–20% of EOCs. This evidence concerns the gene RAD51C and ovarian cancer.