HIF1A and achalasia-alacrima syndrome: Given the activation of Notch signaling induces angiogenesis through increasing the expression of HIF-1α and its target gene VEGF [4,5,12] ,and mural angiogenesis is a prominent pathologic feature in AAAs [23,24], we then performed immunohistochemical staining of aortic aneurysmal tissue with PECAM antibody.