A cell junction that is commonly observed in epithelial (see epithelium) cells (e.g. those lining the intestine and those in cardiac muscle cells). At these junctions the cell membranes of the neighbouring cells are separated by a space of 15–25 nm which is filled with a filamentous material. Beneath this, anchoring the junction to the cell cytoplasm, are loosely structured mats of fibres, 7 nm in diameter, thought to be actin filaments. It is thought that these junctions may provide mobility in the regions of the cells in which they are located.