BRCA1 and neoplasm: Reliable quantification of homologous recombination deficiency of human tumor biopsies, especially in the case of ovarian and breast cancer, is expected to identify patients that are particularly sensitive to platinum or PARP inhibitor-based therapy.1 Before the widespread introduction of next generation sequencing (NGS) to characterize tumor biopsies, SNP arrays were used to identify large-scale genomic aberrations associated with homologous recombination deficiency, often induced by the loss of BRCA1 or BRCA2 function.