The prevalence of chronic airway diseases such as asthma and chronic obstructive pulmonary disease (COPD) was increasing world wide without known reason in the past decades.Beside symptom control by inhaled anti-inflammatory and muscle relaxing drugs no curative therapy is available.Recent studies gave evidence that the cause of these diseases is not a deregulation of the immune response alone,but to a great part involves the physiology of tissue forming structural cells such as airway smooth muscle cells and fibroblasts,however,their biology is poorly understood.In asthma and COPD the expression of distinct isoforms of cell differentiation controlling transcription factors,the C/EBPs,is deregulated on the level of translation.Moreover,this epigenetic effect is induced by inhaled asthma allergens and cigarette smoke (COPD).The mechanism by which this effect becomes persistent is unknown.