TLR7 and chronic obstructive pulmonary disease: The purpose of the current study was to characterize the expression and distribution of TLR3, TLR7, and TLR8 in lung tissue from non-smokers, smokers and smokers with COPD and to analyze the differential effects of roflumilast N-oxide versus corticosteroids and their potential additive or synergistic anti-inflammatory effect in bronchial epithelial cells stimulated with TLR3/7/8 agonists.