['Enterovirus (EV) 71 is an important pathogen causing death in children under 5 years of age worldwide. However, the core pathogenesis remains elusive. We reveal that the protein expression level of vascular endothelial growth factor (VEGF) in EV71 patients was 2-fold higher than in normal controls. However, the origin of VEGF in EV71-infected patients remains unclear.', 'VEGF mRNA and protein expression in four EV71-infected cell lines was evaluated by RT-PCR, ELISA and Western blotting.', 'We found that only mRNA expression of VEGF was increased in the infected cells. Intra- and extracellular VEGF protein expression was decreased or unchanged in the four infected cell lines compared with the uninfected and inactivated EV71-infected cells.'] Does high expression of vascular endothelial growth factor in EV71-infected patients originate from EV71-infected cells?