To examine if some changes in cell signalling or Sulf1/Sulf2 levels during in vivo ischemia were also apparent during in vitro hypoxia, we exposed HMec1 human endothelial cells to 100 μM and 300 μM CoCl2 chemical hypoxia for different lengths of time to examine changes in VEGF levels. Here, SULF2 is linked to ischemia.