BRCA2 and Familial prostate cancer: DARC Sign could feasibly be applied to large correlative efforts from clinical trials testing PARP inhibitors in prostate cancer (e.g. the Prostate Cancer Foundation supported PRECISION Registry; www.precision-registry.com) to clarify whether BRCA2d class membership may indicate particularly therapeutically-vulnerable cancers, including those with non-BRCA2-driven HRR deficiency.