GATA6 and cholangiocarcinoma: Being a transcriptional factor, dysregulation of GATA6 can also result in pathological changes and it was demonstrated that GATA6 alterations implicated in several malignancies such as non-small lung cancer (NSCLC), gastric cancer, cholangiocarcinoma, pancreatic adenocarcinoma or colorectal adenocarcinoma (Zhong et al. 2011; Shen et al. 2013; Tian et al. 2013; Van Baal et al. 2013; Ma et al. 2019).