Hypoxia has also been shown to induce downregulation of MLH1 and PMS2 both in normal cells and in a variety of cancer cells, including hepatocellular, breast, and colon cancer cells (Nakamura et al., 2008; Rodríguez-Jiménez et al., 2008); while the downregulation of MLH1 occurs at the transcription level, that of PMS2 occurs at the protein level probably through destabilization of the protein (Mihaylova et al., 2003). This evidence concerns the gene MLH1 and malignant colon neoplasm.