After ischemia, vascular smooth muscle cells secrete exosomal circRNA cZFP609, which is delivered into endothelial cells, resulting in reduced vascular endothelial growth factor A (VEGFA) expression and disrupted endothelial angiogenic function via the interaction with and sequestration of hypoxia-inducible factor 1 subunit alpha (HIF1α) [142]. The gene discussed is HIF1A; the disease is ischemia.