Figure 1: Gap junction connexins in the growth and progression of breast cancer. (a) In normal mammary gland, epithelial cells and myoepithelial cells maintain intercellular communication through gap junction connexins. (b) During breast cancer growth at primary site, loss of GJIC and low levels of connexins are observed. (c) As the cancer progresses tumor cells regain connexins expression and maintain GJIC with endothelial barrier that induce extravasation and adherence to the metastatic site.