Ren Y, et al. - In patients with chronic obstructive pulmonary disease (COPD), researchers analyzed the expression of cullin4A (CUL4A, an E3 ubiquitin ligase that interacts with other factors to form the E3 complex) in lung epithelium, as well as intended to clarify the regulatory impact and mechanism of CUL4A on epithelial-mesenchymal transformation (EMT) in small airway epithelial cells. They found overexpressed CUL4A in lung epithelium of COPD patients. According to findings, EMT of human small airway epithelium could be regulated by CUL4A.