BRCA1 and cancer: The downregulation of these genes may also beobserved in several other types of cancers, very probably including prostate cancer.In comparison, the TP53 gene (p53) is altered in 40% of breast carcinomascases (Catalogue of Somatic Mutations in Cancer (COSMIC) database: http://www.sanger.ac.uk/genetics/CGP/cosmic/), and although germlinealterations in the BRCA1 and BRCA2 genes are involved in many cases of hereditarybreast and ovarian cancers, the hereditary form of these diseases account for only 5to 10% of the total cases.