PTGS2 and hypertensive disorder: Guo et al. [90], in a study based on gene chip technology, found the overexpression of genes in the heart of the stress-induced hypertensive rat, including heat shock 70 kDa protein (HSPA1A), heat shock protein beta–1 (HSPB1), oxidized low-density lipoprotein receptor 1 (OLR1), phospholipase A2 (PLA2G4A), and prostaglandin-endoperoxide synthase 2 (PTGS2), which are related to the contraction of vascular smooth muscle and may be specific expression genes for hypertension.