We know that the epinephrine that is bound will begin to dissociate and we see that this process takes place with great likelihood only when that epinephrine, the free epinephrine concentration is low. So one method of inactivation involves the epinephrine actually dissociating out of that cavity. Of that seven TM receptor shown here, this is the cavity and this is a seven TM receptor. Now, when the epinephrine concentration drops in the outside bind lashes layers principle to basically compensate for that drop in concentration of the free epinephrine, that epinephrine that is bound actually dissociates. So if we have a high concentration of epinephrine in that extracellular environment in its free form, it will not be likely to dissociate. And that's why we actually have to depend on this second method.