CD4 and asthma: The following keywords were used: human, asthma, allergic asthma, allergy, hyperreactivity, bronchial provocation, methacholine challenge test, excess body weight, obesity, weight gain/loss, inflammation, helper T cell, CD4+ T cells, airway epithelium, eosinophils, innate lymphoid cells, alarmins, and fractioned exhaled nitric oxide (FeNO).