Some studies on ischemic stroke have proposed a hypoxia—HIF‐1α‐LCN2—vascular endothelial growth factor (VEGF)A axis signaling mechanism.23 The HIF‐1α‐LCN2 signaling pathway plays an important role in cancer and acute kidney injury.24, 25 SAH causes a hypoxic state in acute phase due to elevated ICP and decreased CBF.2 Numerous studies have reported that HIF‐1α is expressed in brain in rat models of SAH.26, 27, 28 VEGFA is a potent regulator of endothelial permeability and disruption of the hypoxia—HIF‐1 α‐LCN2—VEGFA axis may help preserve BBB permeability. Here, LCN2 is linked to cancer.