Well, actually, before we examine the functionality of these gap junctions, let's discuss how these gap junctions are actually regulated by ourselves. Because just like voltage gated and ligan gate on channels have to be regulated for the proper functionality of the cells, these gap junctions too have to be regulated. And there are four methods by which we can actually close off these gap junctions. So we can close off these gap junctions by either increasing the concentration of the calcium, increasing the concentration of the h plus ions. So the same thing as saying lowering the PH number three is there are special hormones that can basically induce the process of phosphorylation of these gap junctions. And that too can close off the gap junction.