We found that the expression levels SHMT2, PSAT1, PHGDH, PSPH, CBS, DAO, MAOA, AOC2, GNMT, PIPOX, ALAS2, AOC3 and MAOB were significantly increased in colon cancer tissues compared with those in normal tissues (Supplemental Fig. 2B). This evidence concerns the gene AOC2 and malignant colon neoplasm.