TJP1 and chronic obstructive pulmonary disease: Milara et al. [14] recently reported that mesenchymal markers such as vimentin and α-smooth muscle actin (α-SMA) were upregulated in HBEC from smokers and patients with COPD compared to those from non-smokers while epithelial markers such as E-cadherin and ZO-1 were downregulated, findings consistent with our study.