TRPM4 and angioedema: However, increased expression of SUR1 contributes to vascular injury and plays a role in angioedema, as evidenced by SUR1-TRPM4-mediated death of tumor cells involved in maintaining the structures of the BBB (e.g., astrocytes, endothelial cells), leading to capillary dissection, which exacerbates angioedema and can eventually lead to secondary hemorrhagic progression [40-43].