Connexons may also traffic using a microtubule-independent mechanism. A few studies suggest that rough ER membranes can directly transfer connexons to the plasma membrane (Martin et al. 2001; Bloom and Goldstein 1998). Other cytoskeletal components, such as actin filaments, might be involved in the delivery of connexons to gap junction plaques (Thomas et al. 2001; Gilleron et al. 2006).