The massive accumulation of HIF1α broadly activates the expression of downstream genes and alters the energy metabolism of cells, that is, tumor cells obtain energy through glycolysis under both aerobic and hypoxic conditions (20, 21).The expression of proto oncogene myc and hypoxia inducible factor increased in colorectal cancer and they are key transcription factors of tumor cell glycolysis (22). This evidence concerns the gene HIF1A and colorectal cancer.