MAOB and gastric cancer: Subsequently, NE synthetase enzymes tyrosine hydroxylase (TH), dopa decarboxylase (DDC), and dopamine-β-hydroxylase (DBH), degrading enzymes monoamine oxidase A and B (MAOA and MAOB), and catechol-O-methyl transferase (COMT) were analyzed in TCGA database of gastric cancer.