We read with interest the study by Mansour et al1 in which higher levels of vascular endothelial growth factor (VEGF) were associated with lower risk for acute kidney injury (AKI) and mortality. It is postulated that kidney injury/hypoxia leads to stabilization of hypoxia inducible factor 1α (HIF-1α) and induction of VEGF with subsequent enhancement of angiogenesis, reduced peritubular capillary dropout, and reduced incidence of AKI.2 Observations from our pilot randomized controlled study of 29 patients that investigated the effects of nesiritide on inflammatory response during cardiac surgery3 revealed that the kinetics of individual biomarkers demonstrate unique time-differentiated peak median concentrations.