In addition, a downregulated Wnt4 transcript but not the protein was also observed in PBECs of smoking COPD patients [55], and an enforced expression of Wnt4 could further increase cigarette smoke extract-(CSE-) induced proinflammatory cytokine release in bronchial epithelial cells [55]. The gene discussed is WNT4; the disease is chronic obstructive pulmonary disease.