BRCA1 and neoplasm: To quantify DNA repair deficiency, measurements such as detection of mutations in HRR genes including BRCA1 and BRCA2, the homologous recombination deficiency (HRD) score [8], percent genome wide-LOH [9], tumour mutation burden (TMB) and microsatellite instability (MSI) are increasingly being used to investigate the cause (e.g., a gene mutation) and effect (e.g., HRD score) of deficiencies in DNA repair processes [10–12].