The role of hyperglycaemia in regulating connexin expression [43,44], gap junction communication [45] and hemichannel activity [46,47,48] is well documented [49], and of the 21 isoforms known to be expressed within the human body, Cx43 has been strongly linked to the pathogenesis of multiple secondary complications of diabetes [43,50,51,52]. Here, GJA1 is linked to diabetes mellitus.