Connexins constitute a large family of transmembrane proteins that allow intercellular communication,transfer of ions and small signalling molecules between cells.Gap Junctions are critically important in regulating cell apoptosis and normal cell growth and differentiation.The Cx43 gene sequence remains relatively conserved among species,indicating its presence is very important for survival.Connexin 43 protein plays an important role in normal mammogenesis, lactogenesis and involution. Several studies have shown that downregulation of Connexin 43 protein is involved in primary tumor formation as well as metastasis However,restoration of intercellular communication by the upregulation of Cx43 has been shown to restore normal phenotypes in vitro and reduce tumor growth in vivo. Since the expression profile of Connexin 43 is largely unknown in majority of solid tumors, therefore in this study we evaluate the expression profile of Connexin-43 in breast cancer samples.We have observed down expression of Connexin 43.So it can be applied as a useful diagnostic marker for carcinogenesis