ATF3 knockdown reduced EMT features as indicated by the molecular markers in breast cancer.10 This finding contrasts with other studies in which ATF3 represses EMT in a variety of tumours, including colorectal cancer.16 This study revealed the role of ATF3 in CC, and knockdown of ATF3 robustly down‐regulated the epithelial markers α‐catenin and E‐cadherin, as well as up‐regulated the mesenchymal markers Vimentin and Fibronectin. This evidence concerns the gene FN1 and cholangiocarcinoma.