In COPD, combination of roflumilast N-oxide and dexamethasone was demonstrated to produce additive anti-inflammatory effects in COPD pBECs by increasing the expression of mitogen-activated protein kinase phosphatase 1 (MKP1; also known as dual specificity protein phosphatase 1, (DUSP1) and enhancing inhibitory effects on phospho-p38 and nuclear factor-κB (NFκB) (Milara et al., 2015[21]). Here, NFKB1 is linked to chronic obstructive pulmonary disease.