This peptide corresponds to the GAP27 domain of connexin. Connexins, or gap junctions, are a family of structurally-related transmembrane proteins. Gap junctions contain channels that allow the passage of ions and small molecules between adjacent cells. This intercellular communication has been implicated in the coordination of cellular responses to intracellular signaling molecules. Calcium and inositol phosphates are among the second messengers that can pass through gap junction channels. This synthetic connexin-mimetic peptide, Gap 27, was used to evaluate the contribution of gap-junctional communication to osteoclastic bone resorption. It was concluded that gap-junctional communication is necessary for proper bone remodeling.