Various lines of evidence suggest BARD1 may act as a potent tumor suppressor, including the ability to induce TP53-dependent apoptosis (Irminger-Finger et al., 2001), and the observation that homozygous loss of BARD1 in mice is embryonically lethal, mimicking the properties of BRCA1 (McCarthy et al., 2003). This evidence concerns the gene BRCA1 and neoplasm.