Patients who have mutations of the genes or are at an increased risk for developing breast and ovarian cancer. function as tumor suppressor genes, responsible for regulating DNA repair, and play an essential role in homologous recombination. Mutation of results in homologous recombination deficiency and genomic instability which drives oncogenesis and cancer proliferation. Recently, gene expression has been implicated in regulating immune response. Here we discuss the signaling pathway of BRCA1/2 in relation to breast and ovarian cancer, with emphasis on how dysregulation facilitates the path to malignancy and current treatment options.