A known driver of CIN is defective DNA damage repair, and in the case of HGSOC, possibly up to 50% are homologous recombination deficient (HRD), frequently caused by mutations in the BRCA1 and BRCA2 tumour suppressor genes (TCGA 2011; Denkert et al. 2022; Morgan et al. 2023a). This evidence concerns the gene BRCA1 and neoplasm.