TNF and pulmonary edema: HAPE: high altitude pulmonary edema; TNF-a: tumor necrosis factor-alpha, VEGF: vascular endothelial growth factor, IL: interleukin, SULT1A1: sulfotransferase 1A1, SuPAR: soluble urokinase-type plasminogen activator receptor, CRP: C-reactive protein, HA: high altitude