TP53 and breast cancer: TCGA demonstrated several molecular similarities between TP53 mutated EC and both high-grade serous tubo-ovarian cancer (HGSOC) and basal-like breast cancer.9 Defects in the homologous recombination repair pathway are common in HGSOC and basal-like breast cancers, found in 55% and 46% respectively.46,47 Homologous recombination is essential for the repair of double-stranded DNA breaks, and tumours with homologous recombination deficiency (HRD) are known to be more responsive to both platinum-based chemotherapy and poly (ADP-ribose) polymerase (PARP) inhibitors.