Several cell lines, such as human lung cancer cell A549, normal liver cell line L02, three hepatocarcinoma cell lines SK-Hep-1, HepG2 and BEL-7402, human pancreatic cancer Bx-PC3, and human breast cancer cell MCF-7 were used to measure the expression of B1R and B2R. This evidence concerns the gene BDKRB1 and breast cancer.