With direct comparison of individual expression scores or a median cut-off score, no significant differences in nuclear RAD21 expression were observed between BRCA1 (12 (43%) of 28), BRCA2 (12 (44%) of 27), and BRCAX cancers (12 (33%) of 39) (P = 0.598) (Additional file 2 Table S2a). This evidence concerns the gene BRCA2 and cancer.