MAT1A and cholangiocarcinoma: In hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), MAT1A expression is reduced, and the induction of FOXM1 and NF-κB expression is accompanied by a decrease in MATα1 (the protein encoded by MAT1A) expression, while MATα1 positively regulates the expression of p50 and p65.