CD31 is a key endothelial adhesion protein mediating endothelial integrity and regulation of bioavailability of NO, and angiogenesis (Bagi et al., 2005; Liu et al., 2006; Maas et al., 2005). The histopathological alterations of choroid plexus and cerebral microvasculature in the preeclampsia group of the current study reflect considerable BBB dysfunction which essentially leads to vasogenic edema and subsequent hypertensive encephalopathy. Here, PECAM1 is linked to hypertensive encephalopathy.