Gap Junction (GJ) channels span two plasma membranes and are formed by the alignment of two hemichannels, each consisting of an oligomer of structural subunit proteins, called Cxs (Connexins). These junctional proteins constitute a multigene family whose members are distinguished according to their predicted molecular weight in kilodaltons. A Connexin structure consists of two extracellular loops (EL), four membrane-spanning domains (TM), one cytoplasmic loop (CL), one N-terminal tail (NT), and one C-terminal tail (CT) (Ref.1 & 2). During intercellular channel formation, six Connexins oligomerize into a Connexon or hemichannel that docks in homotypic, heterotypic and combined heterotypic/heteromeric arrangements. In total, as many as 14 different Connexon arrangements can be formed when two members of the Connexin family intermix. This is [...]