CD4 and asthma: To understand the clinical significance of the increased ILC3 frequencies in smoking asthma patients, we analyzed the relationships between the frequencies of sputum ILC3s and blood CD4+CD45RO+ILC3s and asthma severity, as measured by (i) the pulmonary function indices FEV1 and FEV1/FVC ratio or (ii) asthma control, as measured by the ACQ and ACT scores.