BRCA1 and breast cancer: There is increased awareness of hereditary breast and ovarian cancer syndrome (HBOC) among medical professionals, and it has become clear that a relatively high number of Japanese patients have hereditary breast cancer with pathological variants in BRCA1 or BRCA2. [12] A nationwide registry of BRCA genetic test examinees has begun, and the clinical and genetic characteristics of BRCA1 and BRCA2 pathological variant carriers are starting to be clarified.