BRCA1 and neoplasm: At present the biomarkers used to direct the use of PARPi focus on the presence of a deleterious BRCA1 or BRCA2 mutation, a deleterious mutation in other tumour suppressor genes that have been implicated in homologous recombination [68–70], prior platinum sensitivity or the presence in the tumour DNA of a genomic scar of HRD.