BRCA1 and breast cancer: Interestingly, the top five molecular and cellular functions identified by IPA were 'Role of BRCA1 in DNA damage response', 'Mitotic roles of Polo-like kinase', 'Hereditary breast cancer signaling', 'Role of CHK proteins in cell cycle checkpoint control', and 'Cell cycle: G2/M DNA damage checkpoint regulation', which are frequently deregulated in cancer initiation and progression.