VEGFA and Hypertension: Animal studies by Zhu et al. and Li et al. demonstrate that increased venous pressure leads to the upregulation of hypoxia-inducible factor-1 (HIF-1) and subsequent vascular endothelial growth factor (VEGF) expression, initiating within a day and peaking within a week of hypertension onset [8,9,10,11,12,13,14].