Just recently it could be demonstrated that beta 2 agonists may also be able to activate glucocorticosteroid receptors, independently of existing glucocorticosteroids. Thus, beta 2 agonists lead to augmentation of glucocorticosteroid receptor concentration, and consequently cause better efficacy of glucocorticosteroids within the cell. Vice versa glucocorticosteroids enhance the transcription rate of beta 2 receptors, causing higher beta 2 receptor number, and thus may contribute to better beta 2 agonist efficacy. These synergies of beta 2 agonists and glucocorticosteroids on molecular level explain additive efficiency in the therapy of asthma--particularly through improving lung function--when using both substances in combination.