Briefly, at the epithelial level, a large meta-analysis demonstrates that ICS treatment decreases fractional exhaled nitric oxide (FeNO) levels in asthma patients (Blyth et al., 1998), while another meta-analysis shows that COPD patients treated with ICS display shows reduced CD8+ and CD4+ in bronchial biopsies and decreased lymphocyte and neutrophils counts in BALF (Jen et al., 2012). This evidence concerns the gene CD8A and chronic obstructive pulmonary disease.