With respect to FBXO5, Marzio et al. [3] recently determined that reduced FBXO5 expression corresponds with a DNA re-replication phenotype (i.e., endoreduplication) in a breast cancer model and that loss of its F-box dependent function leads to increases in RAD51 abundance (a homologous recombination repair protein). This evidence concerns the gene FBXO5 and breast carcinoma.