HNF1A and hepatocellular carcinoma: HNF1A was shown to bind to the HNF4A promoter region in mouse [20], and mutation in HNF1A demonstrated reduced transactivation activity of its target (HNF4A) promoter [21], which is essential for the differentiation of the hepatic lineage [22] and loss of HNF4A is a critical event in the progression of hepatocellular carcinoma [23].