In the case of infection and hypoxia (13), the glycocalyx of endothelium degrades greatly, and the permeability of endothelium increases, which leads to the leakage of fluid into the tissue space, resulting in tissue edema; endothelial cells can also stimulate leukocytes to release a large number of inflammatory mediators (TNF-α, IL etc.), at the same time, endothelial cells are over apoptotic, stimulate the expression of adhesion molecules, and release oxygen free radicals, further amplify the role of leukocytes. The gene discussed is TNF; the disease is infection.