BRCA2 and cancer: 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.