When the cell normally triggers homologous recombination repair (HRR), a complex signaling pathway involving multiple steps, the most critical proteins are BRCA1 and BRCA2 [50]; thus, cancer patients carrying mutations in the BRCA1 or BRCA2 germline have concurrent HRR malfunctions in their bodies, at which point the cells, in turn, employ other DNA repair methods. This evidence concerns the gene BRCA1 and cancer.