Furthermore, there are several documented cases where the exogenous expression of connexins in a transformed cell line can dramatically suppress its transformed properties and its ability to form tumors in nude mice [Cx43 in C6 glioma cells [11]; Cx43 in 10T1/2 embryonic mesenchymal cells [12]; Cx43 and Cx32 in LNCaP prostate cancer cells [13]; Cx26 in HeLa cervical cancer cells [14]; Cx26 and Cx43 in MDA-MB-231 breast cancer cells [15,16], and; Cx32 in SKHep1 hepatoma cells [17]. This evidence concerns the gene GJB1 and breast carcinoma.