This is the concept for using PARPis to selectively target malignancies with BRCA1/2 germline or somatic mutations, which is termed “synthetic lethality.” This model was supported by two landmark studies published in 2005–BRCA1/2 dysfunction sensitized tumor cells to PARPis in vitro, resulting in selective tumor cell death [26,27]. This evidence concerns the gene BRCA1 and neoplasm.