S the same as sensitivity to dilution or drugs). The mistaken gestalt that sometimes comes to mind is that a stable microtubule is necessarily stiffer or less mobile than a labile microtubule. Some proteins that stabilize microtubules could also make them stiffer or less mobile, but this is not always true. For example, a microtubule could be stable but not as stiff as a microtubule that is labile