Therefore, patients with tumors carrying DNA mismatch repair (MMR) deficiency (MMRd), homologous recombination deficiency (HRD), breast cancer 1/2 (BRCA1/2) genetic defects, or other defects in DDR genes [9], who present more TMB and neoantigens, can benefit from DDRi [11]. This evidence concerns the gene BRCA1 and breast cancer.