It is obvious that in Japanese BC patients like Korean and Cypriot ones [27], the role of BRCA2 mutations is more frequent and important than BRCA1. However, among three founder Japanese alterations, the truncation mutation in codon 63 and an insertion in exon 22 are located in BRCA1 and the third one was found in BRCA2 gene (5802del AATT). This evidence concerns the gene BRCA1 and breast cancer.