Based on the evidence that several players in the ubiquitin-mediated BRCA1-dependent DDR seem to contribute to breast cancer predisposition (summarized in Table 1), we decided to examine the role of RNF8, UBC13 and MMS2 in familial breast cancer by performing a comprehensive mutation screening of these genes in 123 Northern Finnish breast cancer families. This evidence concerns the gene BRCA1 and breast carcinoma.