Carriers of loss of function variants in PALB2 also are associated with high risk of breast cancer.22 In this assay, wild-type BRCA1 protein bound to the VP16–PALB2 fusion protein enhances the transcriptional activation, whereas BRCA1 CC-containing variants that disrupt the interaction with PALB2 fail to exhibit this transcription enhancement (Figure 3a). This evidence concerns the gene BRCA1 and breast cancer.