BRCA1 and cancer: The BRCA1 CC domain interaction with PALB2 is important for cellular response to DNA damage,32 and BRCA1 variants found in cancer patients that disrupt the interaction with the PALB2 protein exhibit defective homologous recombination repair.24 Although it is unclear the extent to which a variant with intermediate effects in a functional assay reflects cancer risk, our analysis suggests that even small differences observed in the TA assay are potentially significant.