A candidate biomarker is the homologous recombination deficiency (HRD) score, which combines three different DNA-based metrics of genomic instability that are highly associated with BRCA1/2 mutational status or predictive of sensitivity to platinum chemotherapy [99]; Richardson et al. [100] demonstrated that the HRD score is able to identify patients with breast tumors with underlying HR deficiency (including BRCA1/2 non-mutated tumors) that benefit from neoadjuvant platinum therapy. The gene discussed is BRCA1; the disease is breast neoplasm.