It will look,in particular, at a protein enzyme called p38 mitogen−activated protein kinase (p38 MAPK for short)which controls the activation of several important pathways in the cell. We wish to find out whether this enzyme is more active in cells obtained from patients with severe asthma compared to those with non−severe asthma. We would like to understand how this enzyme can cause the cell to respond less well to the anti−inflammatory effects of corticosteroids. We also wish to find out whether any specific inhibitors of p38 MAPK can improve severe asthma by improving the effects of corticosteroids on these cells.