GJA1 and breast cancer: Our study investigates the role of ET-induced inflammatory insult in breast cancer initiation events using nontumorigenic (SCp2 and S1) rodent mammary and human breast epithelial cells, respectively, and whether such an insult can “add injury” to pretumorigenic (Cx43-KO S1) or tumorigenic breast cells (MCF-7 and MDA-MB-231).