Range and mean vascular endothelial growth factor-A (VEGF) levels (in pg/mL) in serum samples taken from severe and non severe hemorrhagic fever with renal syndrome (HFRS) cases grouped according to the day after the onset of illness: Group A: 1st week, B: 2nd week, C: 3rd week, D: 4th week, E: >4 weeks. The gene discussed is VEGFA; the disease is hemorrhagic fever with renal syndrome.