A total of 5 cell lines were chosen for study: a) a BRCA1 mutant human ovarian cancer cell line termed UWB1.289 and a stable transformant expressing wild-type BRCA1 protein, termed UWB1.289+BRCA1; and b) wild-type chicken DT40 cells and lines with a BRCA1 or pol β gene deletion and a double knockout cell line for both BRCA1 and pol β genes. This evidence concerns the gene BRCA1 and ovarian carcinoma.