Because PDE4 inhibitors do not modulate RV-induced inflammation or replication this study suggests PDE4 inhibitors may be safe to supplement bronchodilating medication during RV-induced exacerbations of COPD and asthma as well as having other beneficial effects of reducing inflammatory neutrophils during exacerbations of COPD caused by bacteria or viruses other than RV. The gene discussed is PDE4A; the disease is asthma.