We, along with other individual case reports, have observed MGA or IBC-MGA in BRCA1 germline mutation carriers, prompting us to investigate the potential association between IBC-MGA/MGA and BRCA1 germline mutations15,16 and homologous recombination-deficiency (HRD), a process underlying a subset of breast cancers. The gene discussed is BRCA1; the disease is breast cancer.