The participation of T lymphocytes in the pathogenesis of bronchial asthma and the accompanying bronchial hyperreactivity has been widely demonstrated.[25] Indeed, activated CD4+ T lymphocytes are found in the blood and bronchial lumen from asthmatics.[29] Recently, interest has been focused on the characterization of CD4+ T lymphocytes based on their repertoire of secreted cytokines and their possible role in the pathogenesis of allergic disorders. Here, CD4 is linked to asthma.