Connexins in growth control and cancer

Gap junctions, and their constituent connexin proteins, have long been considered to play a role in the control of cell growth and carcinogenesis. The current review will attempt to summarize the evidence supporting the long-held view that gap-junction channels themselves play a preeminent role in controlling cell proliferation and preventing carcinogenesis through mechanisms of direct intercellular communication. In addition, it is timely to address emerging roles of connexin proteins in their own right, not directly in their channel-forming function, i.e., nonjunctional functions.