Hypoxia [29], a representative feature of the tumor microenvironment, can stimulate the transcriptional activation of PPARơ (peroxisome proliferator-activated receptor ơ) through p300 and the PI3K/Akt pathway, leading to the expression of tumor-promoting cytokines, such as CXCL8 and VEGF (vascular endothelial growth factor) [30], which could promote the process of angiogenesis through acting on tumor cells as well as the EC. The gene discussed is CXCL8; the disease is neoplasm.