Two mainly reasons leading to microenvironment hypoxia can be summarized as follows (1):As most tumor cells are in a state of rapid proliferation and high metabolism, oxygen consumption is far greater than supply, resulting in continuous decline of oxygen content in the microenvironment, and finally formation of hypoxia microenvironment (2, 5).Hypoxia tumor cells secrete vascular endothelial growth factor(VEGF)and other pro-vascular factors to accelerate the regeneration of tumor blood vessels. This evidence concerns the gene VEGFA and neoplasm.