Well, in the case of ligand gated ion channels and the voltage gated ion channels, the actual spaces between the two sides of the membrane within the protein. So this space here and this space here is actually relatively small. But for gap junctions, these are relatively wide channels. And these relatively wide channels basically exist between closely packed cells. So let's say this is a cell membrane of one cell, this is a cell membrane of a closely packed adjacent cell, and this is our gap junction. So it basically transverses these two cell membranes.