RAD51 mRNA expression in 16/16 of tumours from BRCA1/2 mutation-negative familial breast cancer patients was found to be one-half of that of the BT-474 breast cancer cell line [14], and protein levels were found to be decreased in 30% of breast tumours from a combination of sporadic and high-risk breast cancer patients [15]. This evidence concerns the gene RAD51 and breast carcinoma.