Wang et al. reported that treatment with BK stimulated B2R and ERK1/2 leading to increased IL-6 production, ultimately increasing the invasiveness of colorectal cancer cells [22]., Ehrenfeld et al. found that activation of the B1R increased secretion of the metalloproteases (MMPs)-2 and − 9 by breast cancer cells [11]. This evidence concerns the gene BDKRB2 and breast cancer.